E - Strictly Positive Matrix

https://codeforces.com/contest/402/submission/175552659

Codeforces/402/E/E.cpp

@@ -0,0 +1,44 @@
+#include <iostream>
+#include <bitset>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2005;
+
+int n;
+std::bitset<N> g[N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1, x; j <= n; j++) {
+            cin >> x;
+
+            g[i][j] = x;
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= n; j++) {
+            if (g[j][i]) g[j] |= g[i];
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        if (g[i].count() != n) {
+            cout << "NO" << endl;
+
+            exit(0);
+        }
+    }
+
+    cout << "YES" << endl;
+
+    return 0;
+}