Submission #563680

#	Time	Username	Problem	Language	Result	Execution time	Memory
563680		mjhmjh1104	Pipes (CEOI15_pipes)	C++17	10 / 100	2059 ms	65536 KiB

pipes

#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int MAX = 100003;

int v, e, cntDfs, dfsN[MAX];
vector<int> adj[MAX];
vector<pair<int, int>> r;

int dfs(int x, int prev = -1) {
    int res = dfsN[x] = cntDfs++;
    for (auto &i: adj[x]) {
        if (i == prev) continue;
        if (dfsN[i]) res = min(res, dfsN[i]);
        else if (!dfsN[i]) {
            int t = dfs(i, x);
            res = min(res, t);
            if (t <= dfsN[x]) continue;
            r.push_back({ x, i });
        }
    }
    return res;
}

int main() {
    scanf("%d%d", &v, &e);
    for (int i = 0; i < e; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for (int i = 0; i < v; i++) if (!dfsN[i]) dfs(i);
    for (auto &i: r) i = make_pair(min(i.first, i.second), max(i.first, i.second));
    sort(r.begin(), r.end());
    for (auto &i: r) printf("%d %d\n", i.first + 1, i.second + 1);
}

Compilation message (stderr)

pipes.cpp: In function 'int main()':
pipes.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |     scanf("%d%d", &v, &e);
      |     ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:31:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         scanf("%d%d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~

• 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