Add Round #395 from CF

Author: jhonber

codeforces/Codeforces Round #395 (Div. 2)/A.cpp

@@ -0,0 +1,26 @@
+// http://codeforces.com/contest/764/problem/A
+
+#include<bits/stdc++.h>
+using namespace std;
+
+#define endl '\n'
+#define D(x) cout << #x << " = " << (x) << endl;
+
+int main() {
+  int n, m, z;
+  cin >> n >> m >> z;
+
+  vector<int> v(z + 1, 0);
+  for (int i = m; i <= z; i += m) {
+    v[i] = 1;
+  }
+
+
+  int ans = 0;
+  for (int i = n; i <= z; i += n) {
+    if (v[i]) ans ++;
+  }
+
+  cout << ans << endl;
+  return 0;
+}

codeforces/Codeforces Round #395 (Div. 2)/B.cpp

@@ -0,0 +1,32 @@
+// http://codeforces.com/contest/764/problem/B
+
+#include<bits/stdc++.h>
+using namespace std;
+
+#define endl '\n'
+#define D(x) cout << #x << " = " << (x) << endl;
+
+int main() {
+  int n;
+  cin >> n;
+
+  vector<int> v(n);
+  for (int i = 0; i < n; ++i) cin >> v[i];
+
+  int a = 0;
+  int b = n - 1;
+
+  int cnt = 0;
+  while (a <= b) {
+    if (cnt % 2 == 0)
+      swap(v[a], v[b]);
+
+    a ++;
+    b --;
+    cnt ++;
+  }
+
+  for (int i = 0; i < n; ++i) cout << v[i] << " "; cout << endl;
+
+  return 0;
+}

codeforces/Codeforces Round #395 (Div. 2)/C.cpp

@@ -0,0 +1,92 @@
+// http://codeforces.com/contest/764/problem/C
+
+#include<bits/stdc++.h>
+using namespace std;
+
+#define endl '\n'
+#define D(x) cout << #x << " = " << (x) << endl;
+
+vector<int> G[110000];
+vector<int> color(110000, 0);
+vector<int> visited(110000, 0);
+
+bool check (int i, int root) {
+  queue<int> Q;
+  Q.push(i);
+
+  while (!Q.empty()) {
+    int cur = Q.front(); Q.pop();
+    visited[cur] = true;
+
+    for (int j = 0; j < G[cur].size(); ++j) {
+      int next = G[cur][j];
+      if (next == root) continue;
+      if (color[next] != color[cur]) return false;
+      if (!visited[next]) {
+        Q.push(next);
+      }
+    }
+  }
+
+  return true;
+}
+
+int main() {
+  int n;
+  cin >> n;
+
+  for (int i = 0; i < n - 1; ++i) {
+    int a, b;
+    cin >> a >> b;
+
+    G[a].push_back(b);
+    G[b].push_back(a);
+  }
+
+  for (int i = 0; i < n; ++i) {
+    int a;
+    cin >> a;
+    color[i + 1] = a;
+  }
+
+  int mm = 0;
+  int bestRoot = -1;
+
+  for (int i = 1; i <= n; ++i) {
+    int cnt = 0;
+    for (int j = 0; j < G[i].size(); ++j) {
+      int child = G[i][j];
+      if (color[child] != color[i]) {
+        cnt ++;
+      }
+    }
+
+    if (cnt > mm) {
+      mm = cnt;
+      bestRoot = i;
+    }
+  }
+
+  if (bestRoot == -1) {
+    cout << "YES" << endl;
+    cout << 1 << endl;
+    return 0;
+  }
+
+  bool ok = true;
+  for (int j = 0; j < G[bestRoot].size(); ++j) {
+    int child = G[bestRoot][j];
+    if (!check(child, bestRoot)) {
+      ok = false;
+      break;
+    }
+  }
+
+  if (ok) {
+    cout << "YES" << endl;
+    cout << bestRoot << endl;
+  }
+  else cout << "NO" << endl;
+
+  return 0;
+}

codeforces/data.db

@@ -919,4 +919,7 @@
 24355390
 24357000
 24126930
-24132337
+24132337
+24366846
+24374352
+24384579