Submission #68126213

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Source Code Expand

/* Author : goats_9 */

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    cin.tie(0)->sync_with_stdio(false);
    int T;
    cin >> T;
    while (T--) {
        int n, m, x, y;
        cin >> n >> m >> x >> y;
        --x, --y;
        vector<set<int>> g(n);
        for (int i = 0; i < m; i++) {
            int u, v;
            cin >> u >> v;
            g[--u].insert(--v);
            g[v].insert(u);
        }
        vector<int> par(n, -1), vis(n);
        auto dfs = [&] (auto&& self, int u, int p) -> void {
            par[u] = p;
            vis[u] = 1;
            for (auto v : g[u]) {
                if (vis[v]) continue;
                self(self, v, u);
            }
        };
        dfs(dfs, x, -1);
        vector<int> path;
        for (int u = y; u != -1; u = par[u])
            path.push_back(u);
        reverse(path.begin(), path.end());
        for (auto u : path)
            cout << u + 1 << ' ';
        cout << '\n';
    }
    return 0;
}

Submission Info

Judge Result