oj.uz

Submission #1028132

# Submission time Handle Problem Language Result Execution time Memory
1028132 2024-07-19T14:12:15 Z vjudge1 Pipes (CEOI15_pipes) C++17
100 / 100
 643 ms 13136 KB 
#include <bits/stdc++.h>

#define ll long long
using namespace std;
const int N = 1e5;
vector < int > adj[N + 2];
struct dsu{
    int par[N + 2];
    int find_par(const int &u){
        if(par[u] < 0)return u;
        par[u] = find_par(par[u]);
        return par[u];
    }
    bool union_set(int u , int v){
        u = find_par(u);
        v = find_par(v);
        if(u != v){
            if(par[u] > par[v])swap(u , v);
            par[u] += par[v];
            par[v] = u;
            return true;
        }
        return false;
    }

} par1 , par2;
int timer = 0;
void dfs(int &u , int p){
    par1.par[u] = par2.par[u] = ++timer;
    for(int &v:adj[u]){
        if(v == p){p = -1; continue;}
        if(!par2.par[v]){
            dfs(v , u);
            par1.par[u] = min(par1.par[u] , par1.par[v]);
            if(par1.par[v] > par2.par[u]){
                cout << u << " " << v <<'\n';
            } 
        }
        else par1.par[u] = min(par1.par[u] , par2.par[v]);

    }
}
void solve() {
    int n , m;
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        par1.par[i] = par2.par[i] = -1;
    }
    for(int i = 1; i <= m ;i ++){
        int u , v;
        cin >> u >> v;
        if(par1.union_set(u , v)){
            adj[u].push_back(v);
            adj[v].push_back(u);
        }
        else if(par2.union_set(u , v)){
            adj[u].push_back(v);
            adj[v].push_back(u);
        }
    }
    for(int  i = 1; i <= n ; i ++){
        par1.par[i] = par2.par[i] = 0;
    }
    for(int i = 1; i <= n ; i++){
        if(!par2.par[i])dfs(i , i);
    }
    
}

signed main() {
    ios::sync_with_stdio(0), cin.tie(0);
    
    #define _ "maxseq."
    if (fopen(_ "inp", "r")) {
        freopen(_ "inp", "r", stdin);
        freopen(_ "out", "w", stdout);
    }
    
    solve();
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(_ "inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
pipes.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         freopen(_ "out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3160 KB Output is correct
2 Correct 2 ms 2652 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3160 KB Output is correct
2 Correct 3 ms 2908 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 2976 KB Output is correct
2 Correct 55 ms 2908 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 95 ms 3664 KB Output is correct
2 Correct 139 ms 3164 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 160 ms 5200 KB Output is correct
2 Correct 134 ms 4684 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 255 ms 10068 KB Output is correct
2 Correct 192 ms 6660 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 361 ms 11208 KB Output is correct
2 Correct 337 ms 8376 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 490 ms 13136 KB Output is correct
2 Correct 454 ms 8336 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 541 ms 13136 KB Output is correct
2 Correct 523 ms 8528 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 632 ms 12628 KB Output is correct
2 Correct 643 ms 9808 KB Output is correct