oj.uz

Submission #156079

# Submission time Handle Problem Language Result Execution time Memory
156079 2019-10-03T07:58:07 Z IOrtroiii 전압 (JOI14_voltage) C++14
0 / 100
 65 ms 19576 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 100100;

int n, m;
vector<int> g[N];
vector<int> tr[N];
int cnt[N];
int ds[N];
int bad;

void dfs1(int v) {
   for (int u : g[v]) {
      if (ds[u] && ds[u] < ds[v] - 1) {
         if ((ds[v] & 1) == (ds[u] & 1)) {
            ++bad;
            cnt[v]++;
            cnt[u]--;
         } else {
            cnt[v]--;
            cnt[u]++;
         }
      } else if (!ds[u]) {
         ds[u] = ds[v] + 1;
         tr[v].emplace_back(u);
         dfs1(u);
      }
   }
}

void dfs2(int v) {
   for (int u : tr[v]) {
      dfs2(u);
      cnt[v] += cnt[u];
   }
}

int main() {
   scanf("%d %d", &n, &m);
   for (int i = 1; i <= m; ++i) {
      int v, u;
      scanf("%d %d", &v, &u);
      g[v].emplace_back(u);
      g[u].emplace_back(v);
   }
   for (int i = 1; i <= n; ++i) {
      if (!ds[i]) {
         ds[i] = 1;
         dfs1(i);
      }
   }
   for (int i = 1; i <= n; ++i) {
      if (ds[i] == 1) {
         dfs2(i);
      }
   }
   int ans = 0;
   for (int i = 1; i <= n; ++i) {
      if (ds[i] > 1 && cnt[i] == bad) {
         ++ans;
      }
   }
   ans += (bad == 1);
   printf("%d\n", ans);
}

Compilation message

voltage.cpp: In function 'int main()':
voltage.cpp:41:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &n, &m);
    ~~~~~^~~~~~~~~~~~~~~~~
voltage.cpp:44:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d %d", &v, &u);
       ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 7 ms 5240 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 55 ms 10992 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 10620 KB Output is correct
2 Correct 60 ms 19456 KB Output is correct
3 Incorrect 64 ms 19576 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
0 / 45.0

# Verdict Execution time Memory Grader output
1 Incorrect 65 ms 11744 KB Output isn't correct
2 Halted 0 ms 0 KB -