Add 剑指Offer06-从尾到头打印链表.c

1-linklist/剑指Offer06-从尾到头打印链表.c

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+//
+// Created by CC on 12/23/20.
+//
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct ListNode{
+    int value;
+    struct ListNode *next;
+}ListNode;
+
+ListNode* createList(int n);
+void travelList(ListNode *pHead);
+//result store in array
+int* reverseList(ListNode *pHead, int* returnSize);
+iteratively or recursively
+struct ListNode* reverseList(struct ListNode* head);
+
+
+int main()
+{
+    ListNode *pList;
+    int *listArray;
+    int n = 5, i, listNumber;
+
+    printf("Please input the number of the 1-linklist: ");
+    scanf("%d", &n);
+    printf("\n");
+    pList = createList(n);
+
+    printf("The travelList is:  ");
+    travelList(pList);
+
+    printf("The reverseList is: ");
+    listArray = reverseList(pList, &listNumber);
+
+    for (i = 0; i <= listNumber - 1; ++i)
+        printf("%d\t", listArray[i]);
+    printf("\n");
+    free(listArray);
+
+    return 0;
+}
+
+
+//create n nodes of 1-linklist
+ListNode* createList(int n)
+{
+    ListNode *pHead, *pNode, *pCurr;
+    int i = 0;
+
+    if (n < 1)
+    {
+        printf("createList FAILURE: n < 1");
+        exit(EXIT_FAILURE);
+    }
+//  create the head of the 1-linklist,
+//  and the head node store the length of the 1-linklist
+    pHead = (ListNode*)malloc(sizeof(ListNode));
+    pCurr = pHead;
+
+    while (i <= n - 1)
+    {
+        pNode = (ListNode*)malloc(sizeof(ListNode));
+        printf("Please input the %dth of %d node: ", i, n);
+        scanf("%d", &pNode->value);
+        pCurr->next = pNode;
+        pCurr = pCurr->next;
+        i++;
+    }
+    pCurr->next = NULL;
+    pHead->value = n;
+
+    return pHead;
+}
+
+void travelList(ListNode *pHead)
+{
+    ListNode *pCurr;
+
+    if (pHead == NULL)
+    {
+        printf("travelList FAILURE: pHead is NULL");
+        exit(EXIT_FAILURE);
+    }
+
+    pCurr = pHead -> next;
+    while (pCurr != NULL)
+    {
+        printf("%d\t", pCurr->value);
+        pCurr = pCurr->next;
+    }
+    printf("\n");
+}
+
+int* reverseList(ListNode *pHead, int* returnSize)
+{
+    ListNode *pCurr;
+    int number = 0, i;
+
+    if (pHead == NULL )
+    {
+        printf("reverseList FAILURE: pHead is NULL");
+        exit(EXIT_FAILURE);
+    }
+    if (returnSize == NULL)
+    {
+        printf("reverseList FAILURE: returnSize is NULL");
+        exit(EXIT_FAILURE);
+    }
+
+    pCurr = pHead->next;
+    //First walk all nodes in order to get the number of the 1-linklist
+    while (pCurr != NULL)
+    {
+        number++;
+        pCurr = pCurr -> next;
+    }
+    int *returnArray = (int *)malloc(sizeof(int) * number);
+
+    pCurr = pHead->next;
+    // walk all nodes in order and reversely store in the array returnArray
+    for (i = number - 1; pCurr != NULL; i--)
+    {
+        returnArray[i] = pCurr->value;
+        pCurr = pCurr->next;
+    }
+    *returnSize = number;
+
+    return returnArray;
+}