Submission #527269

#	Time	Username	Problem	Language	Result	Execution time	Memory
527269		ecxx	Pipes (CEOI15_pipes)	C++17	10 / 100	2944 ms	65540 KiB

pipes

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;

int* depth = new int[MAXN]{0};
int* low = new int[MAXN]{0};
int* pos = new int[MAXN];
int* edgelist;

void AP(int i, int d, int pa) {
    depth[i] = d; low[i] = d;
    int paedges = 0;
    for (int k = pos[i]; k < pos[i+1]; k++) {
        int ch = edgelist[k];
        //cout << i << " " << ch << " " << pa << " p" << endl;
        if (ch==pa) {
            paedges++;
            continue;
        }
        if (depth[ch] != -1) {
            low[i] = min(low[i], depth[ch]);
        } else {
            AP(ch, d+1, i);
            low[i] = min(low[i], low[ch]);
        }
    }
    //cout << i << " " << pa << " " << paedges << endl;
    if (pa==-1) return;
    if (low[i] > depth[pa] && paedges == 1) {
        cout << i+1 << " " << pa+1 << "\n";
    }
}

int main() {

    int N, M, a, b; cin >> N >> M;
    pair<int,int>* EL;
    EL = new pair<int,int>[2*M];

    for (int i = 0; i < M; i++) {
        cin >> a >> b; a--;b--;
        EL[2*i] = {a,b};
        EL[2*i+1] = {b,a};
    }

    sort(EL, EL+(2*M));

    int curri = -1;
    int q = 0;

    edgelist = new int[2*M+5];

    for (int k=0;k<2*M;k++) {
        auto a = EL[k];
        if (a.first != curri) { 
            pos[a.first] = q;
            curri = a.first;
        }
        edgelist[q] = a.second;
        q++;
    }

    pos[curri+1] = q;

    delete[] EL;

    for (int i = 0; i < N; i++) {
        depth[i] = -1;
    }

    for (int i = 0; i < N; i++) {
        if (depth[i] == -1)  AP(i,0,-1);
    }

}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10