Solve problem 44. Check DFS from csacademy

Author: AliOsm

CS Academy/44. Check DFS.cpp

@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <vector>
+
+using namespace std;
+
+int const N = 1e5 + 1;
+int n, m, p[N], order[N], dfs, dfs_order[N];
+bool vis[N];
+vector<vector<int> > g;
+
+bool cmp(int a, int b) {
+	return order[a] < order[b];
+}
+
+void DFS(int v) {
+	dfs_order[dfs++] = v;
+	vis[v] = true;
+	for(int i = 0; i < (int)g[v].size(); ++i)
+		if(!vis[g[v][i]])
+			DFS(g[v][i]);
+}
+
+int main() {
+	scanf("%d %d", &n, &m);
+	for(int i = 0; i < n; ++i) {
+		scanf("%d", p + i);
+		order[p[i]] = i;
+	}
+	g.resize(n + 1);
+	for(int i = 0, a, b; i < m; ++i) {
+		scanf("%d %d", &a, &b);
+		g[a].push_back(b);
+		g[b].push_back(a);
+	}
+
+	for(int i = 0; i < (int)g.size(); ++i)
+		sort(g[i].begin(), g[i].end(), cmp);
+
+	DFS(1);
+
+	bool ok = true;
+	for(int i = 0; i < n; ++i)
+		if(p[i] != dfs_order[i]) {
+			ok = false;
+			break;
+		}
+
+	printf("%d\n", ok);
+
+    return 0;
+}
+

CS Academy/README.md

@@ -9,3 +9,4 @@
 - [40. Move the Bishop](https://csacademy.com/contest/round-40/task/move-the-bishop)
 - [44. Frequent Numbers](https://csacademy.com/contest/round-44/task/frequent-numbers)
 - [44. Square Cover](https://csacademy.com/contest/round-44/task/square-cover)
+- [44. Check DFS](https://csacademy.com/contest/round-44/task/check-dfs)