diff --git a/README.md b/README.md
index 148b030c..8ef2b250 100644
--- a/README.md
+++ b/README.md
@@ -471,7 +471,7 @@ This repo is a collection of my LeetCode solutions, primarily written in Python,
 | 2666 | [Allow One Function Call](<https://leetcode.com/problems/allow-one-function-call>)                                                                                                         | Easy    |                | [solution](<markdowns/_2666. Allow One Function Call.md>)                                                     | js                                          |
 | 2667 | [Create Hello World Function](<https://leetcode.com/problems/create-hello-world-function>)                                                                                                 | Easy    |                | [solution](<markdowns/_2667. Create Hello World Function.md>)                                                 | js                                          |
 | 2671 | [Frequency Tracker](<https://leetcode.com/problems/frequency-tracker>)                                                                                                                     | Medium  |                | [solution](<markdowns/_2671. Frequency Tracker.md>)                                                           | py                                          |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<markdowns/_2678. Number of Senior Citizens.md>)                                                   | java, py                                    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<markdowns/_2678. Number of Senior Citizens.md>)                                                   | c, java, py                                 |
 | 2679 | [Sum in a Matrix](<https://leetcode.com/problems/sum-in-a-matrix>)                                                                                                                         | Medium  |                | [solution](<markdowns/_2679. Sum in a Matrix.md>)                                                             | java                                        |
 | 2703 | [Return Length of Arguments Passed](<https://leetcode.com/problems/return-length-of-arguments-passed>)                                                                                     | Easy    |                | [solution](<markdowns/_2703. Return Length of Arguments Passed.md>)                                           | js, ts                                      |
 | 2704 | [To Be Or Not To Be](<https://leetcode.com/problems/to-be-or-not-to-be>)                                                                                                                   | Easy    |                | [solution](<markdowns/_2704. To Be Or Not To Be.md>)                                                          | js                                          |
diff --git a/markdowns/Daily_Questions.md b/markdowns/Daily_Questions.md
index 375efbdf..bb82e593 100644
--- a/markdowns/Daily_Questions.md
+++ b/markdowns/Daily_Questions.md
@@ -6,7 +6,7 @@ Dates are for the date I completed the question so due to the my time zone and h
 
 |    # | Title                                                                                                                                                                                      | Level   | Cats        | Solution                                                                                            | Languages                    | Date Complete   |
 |-----:|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:--------|:------------|:----------------------------------------------------------------------------------------------------|:-----------------------------|:----------------|
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily       | [solution](<_2678. Number of Senior Citizens.md>)                                                   | java, py                     | Aug 01, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily       | [solution](<_2678. Number of Senior Citizens.md>)                                                   | c, java, py                  | Aug 01, 2024    |
 | 1105 | [Filling Bookcase Shelves](<https://leetcode.com/problems/filling-bookcase-shelves>)                                                                                                       | Medium  | Daily       | [solution](<_1105. Filling Bookcase Shelves.md>)                                                    | py                           | Jul 31, 2024    |
 | 1653 | [Minimum Deletions to Make String Balanced](<https://leetcode.com/problems/minimum-deletions-to-make-string-balanced>)                                                                     | Medium  | Daily       | [solution](<_1653. Minimum Deletions to Make String Balanced.md>)                                   | py                           | Jul 30, 2024    |
 | 1395 | [Count Number of Teams](<https://leetcode.com/problems/count-number-of-teams>)                                                                                                             | Medium  | Daily       | [solution](<_1395. Count Number of Teams.md>)                                                       | py                           | Jul 29, 2024    |
diff --git a/markdowns/Easy.md b/markdowns/Easy.md
index 4b6d76a1..4f990fbb 100644
--- a/markdowns/Easy.md
+++ b/markdowns/Easy.md
@@ -129,7 +129,7 @@
 | 2665 | [Counter II](<https://leetcode.com/problems/counter-ii>)                                                                                                           | Easy    |           | [solution](<_2665. Counter II.md>)                                                      | js                           | Jul 09, 2024    |
 | 2666 | [Allow One Function Call](<https://leetcode.com/problems/allow-one-function-call>)                                                                                 | Easy    |           | [solution](<_2666. Allow One Function Call.md>)                                         | js                           | Jul 09, 2024    |
 | 2667 | [Create Hello World Function](<https://leetcode.com/problems/create-hello-world-function>)                                                                         | Easy    |           | [solution](<_2667. Create Hello World Function.md>)                                     | js                           | Jul 09, 2024    |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                             | Easy    | Daily     | [solution](<_2678. Number of Senior Citizens.md>)                                       | java, py                     | May 22, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                             | Easy    | Daily     | [solution](<_2678. Number of Senior Citizens.md>)                                       | c, java, py                  | May 22, 2024    |
 | 2703 | [Return Length of Arguments Passed](<https://leetcode.com/problems/return-length-of-arguments-passed>)                                                             | Easy    |           | [solution](<_2703. Return Length of Arguments Passed.md>)                               | js, ts                       | Jul 09, 2024    |
 | 2704 | [To Be Or Not To Be](<https://leetcode.com/problems/to-be-or-not-to-be>)                                                                                           | Easy    |           | [solution](<_2704. To Be Or Not To Be.md>)                                              | js                           | Jul 09, 2024    |
 | 2723 | [Add Two Promises](<https://leetcode.com/problems/add-two-promises>)                                                                                               | Easy    |           | [solution](<_2723. Add Two Promises.md>)                                                | js                           | Jul 09, 2024    |
diff --git a/markdowns/Questions_By_Code_Length.md b/markdowns/Questions_By_Code_Length.md
index 6814be71..41a223c7 100644
--- a/markdowns/Questions_By_Code_Length.md
+++ b/markdowns/Questions_By_Code_Length.md
@@ -226,6 +226,7 @@ Calculations are based on the code files's byte sizes.
 |  744 | [Find Smallest Letter Greater Than Target](<https://leetcode.com/problems/find-smallest-letter-greater-than-target>)                                                                       | Easy    |                | [solution](<_744. Find Smallest Letter Greater Than Target.md>)                                     | java, py                                    | Jun 01, 2024    |
 |   77 | [Combinations](<https://leetcode.com/problems/combinations>)                                                                                                                               | Medium  |                | [solution](<_77. Combinations.md>)                                                                  | py                                          | Jun 07, 2024    |
 |  125 | [Valid Palindrome](<https://leetcode.com/problems/valid-palindrome>)                                                                                                                       | Easy    | B75, N150      | [solution](<_125. Valid Palindrome.md>)                                                             | c, py                                       | Jun 07, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<_2678. Number of Senior Citizens.md>)                                                   | c, java, py                                 | May 22, 2024    |
 | 1905 | [Count Sub Islands](<https://leetcode.com/problems/count-sub-islands>)                                                                                                                     | Medium  |                | [solution](<_1905. Count Sub Islands.md>)                                                           | py                                          | Jun 24, 2024    |
 | 1791 | [Find Center of Star Graph](<https://leetcode.com/problems/find-center-of-star-graph>)                                                                                                     | Easy    | Daily          | [solution](<_1791. Find Center of Star Graph.md>)                                                   | c, cpp, java, py                            | Jun 27, 2024    |
 |  993 | [Cousins in Binary Tree](<https://leetcode.com/problems/cousins-in-binary-tree>)                                                                                                           | Easy    |                | [solution](<_993. Cousins in Binary Tree.md>)                                                       | py                                          | Jul 04, 2024    |
@@ -293,7 +294,6 @@ Calculations are based on the code files's byte sizes.
 | 1858 | [Longest Word With All Prefixes](<https://leetcode.com/problems/longest-word-with-all-prefixes>)                                                                                           | Medium  |                | [solution](<_1858. Longest Word With All Prefixes.md>)                                              | py                                          | Jun 29, 2024    |
 |   49 | [Group Anagrams](<https://leetcode.com/problems/group-anagrams>)                                                                                                                           | Medium  | B75, N150      | [solution](<_49. Group Anagrams.md>)                                                                | py                                          | Jun 13, 2024    |
 | 1455 | [Check If a Word Occurs As a Prefix of Any Word in a Sentence](<https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence>)                               | Easy    |                | [solution](<_1455. Check If a Word Occurs As a Prefix of Any Word in a Sentence.md>)                | py                                          | Jun 01, 2024    |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<_2678. Number of Senior Citizens.md>)                                                   | java, py                                    | May 22, 2024    |
 | 1929 | [Concatenation of Array](<https://leetcode.com/problems/concatenation-of-array>)                                                                                                           | Easy    |                | [solution](<_1929. Concatenation of Array.md>)                                                      | c, java, py                                 | Jun 03, 2024    |
 | 1026 | [Maximum Difference Between Node and Ancestor](<https://leetcode.com/problems/maximum-difference-between-node-and-ancestor>)                                                               | Medium  |                | [solution](<_1026. Maximum Difference Between Node and Ancestor.md>)                                | py                                          | Jun 23, 2024    |
 |  776 | [Split BST](<https://leetcode.com/problems/split-bst>)                                                                                                                                     | Medium  | Weekly Premium | [solution](<_776. Split BST.md>)                                                                    | py                                          | Jun 29, 2024    |
diff --git a/markdowns/Questions_By_Recent.md b/markdowns/Questions_By_Recent.md
index 8f215da2..1da10489 100644
--- a/markdowns/Questions_By_Recent.md
+++ b/markdowns/Questions_By_Recent.md
@@ -462,7 +462,7 @@ Calculations are based on the date of the first solve.
 |    2 | [Add Two Numbers](<https://leetcode.com/problems/add-two-numbers>)                                                                                                                         | Medium  | N150           | [solution](<_2. Add Two Numbers.md>)                                                                | java                                        | May 22, 2024    |
 |  176 | [Second Highest Salary](<https://leetcode.com/problems/second-highest-salary>)                                                                                                             | Medium  |                | [solution](<_176. Second Highest Salary.md>)                                                        | sql                                         | May 22, 2024    |
 |  577 | [Employee Bonus](<https://leetcode.com/problems/employee-bonus>)                                                                                                                           | Easy    |                | [solution](<_577. Employee Bonus.md>)                                                               | sql                                         | May 22, 2024    |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<_2678. Number of Senior Citizens.md>)                                                   | java, py                                    | May 22, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                     | Easy    | Daily          | [solution](<_2678. Number of Senior Citizens.md>)                                                   | c, java, py                                 | May 22, 2024    |
 |   26 | [Remove Duplicates from Sorted Array](<https://leetcode.com/problems/remove-duplicates-from-sorted-array>)                                                                                 | Easy    |                | [solution](<_26. Remove Duplicates from Sorted Array.md>)                                           | java                                        | May 22, 2024    |
 |   21 | [Merge Two Sorted Lists](<https://leetcode.com/problems/merge-two-sorted-lists>)                                                                                                           | Easy    | B75, N150      | [solution](<_21. Merge Two Sorted Lists.md>)                                                        | java                                        | May 22, 2024    |
 |   20 | [Valid Parentheses](<https://leetcode.com/problems/valid-parentheses>)                                                                                                                     | Easy    | B75, N150      | [solution](<_20. Valid Parentheses.md>)                                                             | java                                        | May 22, 2024    |
diff --git a/markdowns/_2678. Number of Senior Citizens.md b/markdowns/_2678. Number of Senior Citizens.md
index bf241e3f..5d9cb71c 100644
--- a/markdowns/_2678. Number of Senior Citizens.md	
+++ b/markdowns/_2678. Number of Senior Citizens.md	
@@ -20,10 +20,25 @@
 
 ## Solutions
 
+- [e2678 v1.c](<../my-submissions/e2678 v1.c>)
 - [e2678 v1.py](<../my-submissions/e2678 v1.py>)
 - [e2678 v2 oneliner.py](<../my-submissions/e2678 v2 oneliner.py>)
 - [e2678 v3 oneliner.py](<../my-submissions/e2678 v3 oneliner.py>)
 - [e2678.java](<../my-submissions/e2678.java>)
+### C
+#### [e2678 v1.c](<../my-submissions/e2678 v1.c>)
+```C
+int countSeniors(char ** details, int detailsSize){
+    int output = 0;
+    for (int i = 0; i < detailsSize; i++) {
+        if ((details[i][11] - '0') * 10 + details[i][12] - '0' > 60) {
+            output++;
+        }
+    }
+    return output;
+}
+```
+
 ### Python
 #### [e2678 v1.py](<../my-submissions/e2678 v1.py>)
 ```Python
diff --git a/markdowns/by_topic/Array.md b/markdowns/by_topic/Array.md
index 4ad67be3..492583b4 100644
--- a/markdowns/by_topic/Array.md
+++ b/markdowns/by_topic/Array.md
@@ -199,7 +199,7 @@
 | 2545 | [Sort the Students by Their Kth Score](<https://leetcode.com/problems/sort-the-students-by-their-kth-score>)                                                                             | Medium  |                | [solution](<../_2545. Sort the Students by Their Kth Score.md>)                                       | java, py                     | Jun 24, 2024    |
 | 2570 | [Merge Two 2D Arrays by Summing Values](<https://leetcode.com/problems/merge-two-2d-arrays-by-summing-values>)                                                                           | Easy    |                | [solution](<../_2570. Merge Two 2D Arrays by Summing Values.md>)                                      | c                            | Jun 10, 2024    |
 | 2610 | [Convert an Array Into a 2D Array With Conditions](<https://leetcode.com/problems/convert-an-array-into-a-2d-array-with-conditions>)                                                     | Medium  |                | [solution](<../_2610. Convert an Array Into a 2D Array With Conditions.md>)                           | py                           | Jun 07, 2024    |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                   | Easy    | Daily          | [solution](<../_2678. Number of Senior Citizens.md>)                                                  | java, py                     | May 22, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                                   | Easy    | Daily          | [solution](<../_2678. Number of Senior Citizens.md>)                                                  | c, java, py                  | May 22, 2024    |
 | 2679 | [Sum in a Matrix](<https://leetcode.com/problems/sum-in-a-matrix>)                                                                                                                       | Medium  |                | [solution](<../_2679. Sum in a Matrix.md>)                                                            | java                         | May 22, 2024    |
 | 2751 | [Robot Collisions](<https://leetcode.com/problems/robot-collisions>)                                                                                                                     | Hard    | Daily          | [solution](<../_2751. Robot Collisions.md>)                                                           | py                           | Jul 13, 2024    |
 | 2942 | [Find Words Containing Character](<https://leetcode.com/problems/find-words-containing-character>)                                                                                       | Easy    |                | [solution](<../_2942. Find Words Containing Character.md>)                                            | c                            | Jun 06, 2024    |
diff --git a/markdowns/by_topic/String.md b/markdowns/by_topic/String.md
index ff186c6f..51a23f0c 100644
--- a/markdowns/by_topic/String.md
+++ b/markdowns/by_topic/String.md
@@ -97,7 +97,7 @@
 | 2418 | [Sort the People](<https://leetcode.com/problems/sort-the-people>)                                                                                                       | Easy    | Daily          | [solution](<../_2418. Sort the People.md>)                                                    | py          | Jul 22, 2024    |
 | 2423 | [Remove Letter To Equalize Frequency](<https://leetcode.com/problems/remove-letter-to-equalize-frequency>)                                                               | Easy    |                | [solution](<../_2423. Remove Letter To Equalize Frequency.md>)                                | py          | Jun 17, 2024    |
 | 2486 | [Append Characters to String to Make Subsequence](<https://leetcode.com/problems/append-characters-to-string-to-make-subsequence>)                                       | Medium  | Daily          | [solution](<../_2486. Append Characters to String to Make Subsequence.md>)                    | c, java, py | Jun 03, 2024    |
-| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                   | Easy    | Daily          | [solution](<../_2678. Number of Senior Citizens.md>)                                          | java, py    | May 22, 2024    |
+| 2678 | [Number of Senior Citizens](<https://leetcode.com/problems/number-of-senior-citizens>)                                                                                   | Easy    | Daily          | [solution](<../_2678. Number of Senior Citizens.md>)                                          | c, java, py | May 22, 2024    |
 | 2734 | [Lexicographically Smallest String After Substring Operation](<https://leetcode.com/problems/lexicographically-smallest-string-after-substring-operation>)               | Medium  |                | [solution](<../_2734. Lexicographically Smallest String After Substring Operation.md>)        | py          | Jun 29, 2024    |
 | 2743 | [Count Substrings Without Repeating Character](<https://leetcode.com/problems/count-substrings-without-repeating-character>)                                             | Medium  | Weekly Premium | [solution](<../_2743. Count Substrings Without Repeating Character.md>)                       | java, py    | Jun 22, 2024    |
 | 2942 | [Find Words Containing Character](<https://leetcode.com/problems/find-words-containing-character>)                                                                       | Easy    |                | [solution](<../_2942. Find Words Containing Character.md>)                                    | c           | Jun 06, 2024    |