19-miniron-v

miniron-v/README.md

@@ -20,4 +20,6 @@
 | 15차시 | 2024.02.15 |  DP, 큰 수 연산  | [타일링](https://www.acmicpc.net/problem/1793)  | [#56](https://github.com/AlgoLeadMe/AlgoLeadMe-5/pull/56) |
 | 16차시 | 2024.02.18 |  수학  | [합](https://www.acmicpc.net/problem/1081)  | [#61](https://github.com/AlgoLeadMe/AlgoLeadMe-5/pull/61) |
 | 17차시 | 2024.02.21 |  DP  | [제곱수의 합](https://www.acmicpc.net/problem/1699)  | [#64](https://github.com/AlgoLeadMe/AlgoLeadMe-5/pull/64) |
+| 18차시 | 2024.02.24 |  이분 탐색  | [K번째 수](https://www.acmicpc.net/problem/1300)  | [#66](https://github.com/AlgoLeadMe/AlgoLeadMe-5/pull/66) |
+| 19차시 | 2024.02.27 |  다익스트라  | [최단경로](https://www.acmicpc.net/problem/1753)  | [#70](https://github.com/AlgoLeadMe/AlgoLeadMe-5/pull/70) |
 ---

miniron-v/다익스트라/1753-최단경로.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+
+const int INF = 3000001;
+
+std::vector<int> dijkstra(int start, int n, std::vector<std::vector<std::pair<int, int>>>& graph) {
+	std::vector<int> min_weight(n + 1, INF);
+	std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, std::greater<std::pair<int, int>>> pq;
+
+	min_weight[start] = 0;
+	pq.push({ 0, start });
+
+	while (pq.empty() == false) {
+		int cur_weight = pq.top().first;
+		int cur_node = pq.top().second;
+		pq.pop();
+
+		for (auto& pair : graph[cur_node]) {
+			int next_node = pair.first;
+			int next_weight = cur_weight + pair.second;
+
+			if (next_weight < min_weight[next_node]) {
+				min_weight[next_node] = next_weight;
+				pq.push({ next_weight, next_node});
+			}
+		}
+	}
+
+	return min_weight;
+}
+
+int main() {
+	// 입력
+	int V, E, start;
+	std::cin >> V >> E >> start;
+
+	std::vector<std::vector<std::pair<int, int>>> graph(V + 1);
+	for (int i = 0; i < E; ++i) {
+		int u, v, w;
+		std::cin >> u >> v >> w;
+
+		graph[u].push_back({v, w});
+	}
+
+	// 계산
+	std::vector<int> min_weight = dijkstra(start, V, graph);
+
+	// 출력
+	for (int i = 1; i < min_weight.size(); ++i) {
+		if (min_weight[i] == INF) {
+			std::cout << "INF\n";
+			continue;
+		}
+
+		std::cout << min_weight[i] << "\n";
+	}
+}

miniron-v/이분 탐색/1300-K번째 수.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+
+// [n][n] 배열에서 upper 이하 수의 개수를 센다.
+long countNum(long n, long upper) {
+	long count = 0;
+
+	for (long i = 1; i <= n && i <= upper; ++i) {
+		count += std::min(upper / i, n);
+	}
+
+	return count;
+}
+
+int main() {
+	long n, k;
+	std::cin >> n >> k;
+
+	long low = 0, high = k;
+	long mid = 0;
+
+	while (low + 1 < high) {
+		mid = (low + high) / 2;
+		long count = countNum(n, mid);
+
+		if (count < k) {
+			low = mid;
+		}
+
+		else if (count >= k) {
+			high = mid;
+		}
+	}
+
+	std::cout << high;
+}