oj.uz

Submission #244462

# Submission time Handle Problem Language Result Execution time Memory
244462 2020-07-04T06:33:46 Z dwsc Potemkin cycle (CEOI15_indcyc) C++14
10 / 100
 1000 ms 1400 KB 
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
int n,m;
vector<int> adj[1010];
int depth[1010],p[1010][10];
int lowest[1010][11];
int relabel[1010];
int counter;
void dfs(int u,int pa){
    //cout << u << pa << "hi\n";
    depth[u] = depth[pa]+1;
    p[u][0] = pa;
    for (int i = 1; i <= 10; i++){
        if (p[u][i-1] == 0) p[u][i] = 0;
        else p[u][i] = p[p[u][i-1]][i-1];
    }
    for (int i = 0; i < adj[u].size(); i++){
        int v = adj[u][i];
        if (depth[v] != 0) continue;
        dfs(v,u);
    }
    relabel[u] = ++counter;
}
int lowestjump[1010];
int main(){
    cin >> n >> m;
    for (int i = 0; i < m; i++){
        int x,y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for (int i = 1; i <= n; i++){
        if (p[i][0] == 0) dfs(i,0);
    }
    vector<ii> backedges;
    for (int i = 1; i <= n; i++){
        lowestjump[i] = 1e9;
        for (int j = 0; j < adj[i].size(); j++){
            int ni = adj[i][j];
            if (p[ni][0] == i || p[i][0] == ni) continue;
            if (depth[i] < depth[ni]) continue;
            lowestjump[i] = min(lowestjump[i],relabel[ni]);
            if (depth[i]-depth[ni] >= 3) backedges.push_back(ii(i,ni));
        }
    }
    for (int i = 0; i < backedges.size(); i++){
        int minjump = 1e9;
        int start = backedges[i].first, fin = backedges[i].second;
        if (lowestjump[start] != relabel[fin]) continue;
        int temp = start;
        while (temp != fin){
            temp = p[temp][0];
            minjump = min(minjump,lowestjump[temp]);
        }
        if (minjump <= relabel[fin]) continue;
        cout << start << " ";
        while (start != fin){
            start = p[start][0];
            cout << start << " ";
        }
        return 0;
    }
    cout << "no";
    return 0;
}

Compilation message

indcyc.cpp: In function 'void dfs(int, int)':
indcyc.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < adj[u].size(); i++){
                     ~~^~~~~~~~~~~~~~~
indcyc.cpp: In function 'int main()':
indcyc.cpp:40:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < adj[i].size(); j++){
                         ~~^~~~~~~~~~~~~~~
indcyc.cpp:48:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < backedges.size(); i++){
                     ~~^~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1096 ms 384 KB Time limit exceeded

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1093 ms 384 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1097 ms 384 KB Time limit exceeded

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1096 ms 384 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1094 ms 384 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1091 ms 384 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1097 ms 1016 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1094 ms 640 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1092 ms 1400 KB Time limit exceeded
2 Halted 0 ms 0 KB -