Submission #74770864

---

Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, m;
    if (!(cin >> n >> m)) return 0;

    vector<int> r(n + 1);
    vector<pair<int, int>> participants(n);
    for (int i = 1; i <= n; ++i) {
        cin >> r[i];
        participants[i - 1] = {r[i], i};
    }

    sort(participants.begin(), participants.end(), [](const pair<int, int>& a, const pair<int, int>& b) {
        return a.first > b.first;
    });

    vector<vector<int>> adj(n + 1);
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 1; i <= n; ++i) {
        sort(adj[i].begin(), adj[i].end());
    }

    vector<bool> paired(n + 1, false); 
    vector<int> ptr(n + 1, 0);         
    int ans_for_aoki = -1;             

    for (int i = 0; i < n; ++i) {
        int x = participants[i].second;
        
        if (paired[x]) continue;

        while (ptr[x] < adj[x].size() && paired[adj[x][ptr[x]]]) {
            ptr[x]++;
        }
        int y = adj[x][ptr[x]];
        
        paired[x] = true;
        paired[y] = true;

        if (x == 1) ans_for_aoki = y;
        if (y == 1) ans_for_aoki = x;
    }

    cout << ans_for_aoki << "\n";

    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function 'int main()':
./Main.cpp:45:23: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |         while (ptr[x] < adj[x].size() && paired[adj[x][ptr[x]]]) {

Judge Result