oj.uz

Submission #581730

# Submission time Handle Problem Language Result Execution time Memory
581730 2022-06-23T05:16:44 Z 박상훈(#8364) 전압 (JOI14_voltage) C++14
0 / 100
 62 ms 8640 KB 
#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
vector<int> adj[100100];
pair<int, int> E[200200];
int n, m, visited[200200];

bool dfs_col(int s, int c = 0){
    visited[s] = c;
    for (auto &v:adj[s]){
        if (visited[v]<0){
            if (!dfs_col(v, c^1)) return 0;
        }
        else if (visited[v]==c) return 0;
    }
    return 1;
}

void naive(){
    int ans = 0;
    for (int i=1;i<=m;i++){
        for (int j=1;j<=n;j++) adj[j].clear();
        for (int j=1;j<=m;j++) if (i!=j){
            adj[E[j].first].push_back(E[j].second);
            adj[E[j].second].push_back(E[j].first);
        }

        fill(visited+1, visited+n+1, -1);
        visited[E[i].first] = visited[E[i].second] = 0;
        bool flag = 1;
        flag &= dfs_col(E[i].first);
        if (visited[E[i].second] < 0) flag &= dfs_col(E[i].second);

        for (int j=1;j<=n;j++) if (visited[j]<0) flag &= dfs_col(j);
        if (flag) ans++;
    }
    printf("%d\n", ans);
    exit(0);
}

int main(){
    scanf("%d %d", &n, &m);
    for (int i=1;i<=m;i++){
        int x, y;
        scanf("%d %d", &x, &y);
        adj[x].push_back(y);
        adj[y].push_back(x);
        E[i] = {x, y};
    }

    if (n<=1000) naive();

    return 0;
}

Compilation message

voltage.cpp: In function 'int main()':
voltage.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
voltage.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 62 ms 2712 KB Output is correct
2 Correct 56 ms 2684 KB Output is correct
3 Incorrect 44 ms 2644 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 32 ms 6844 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 35.0

# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 6932 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 45.0

# Verdict Execution time Memory Grader output
1 Incorrect 46 ms 8640 KB Output isn't correct
2 Halted 0 ms 0 KB -