Flowery Trails

input/code.cpp: In function 'int main()':
input/code.cpp:46:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); i++) {
                                ^

#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define N 11111

using namespace std;

vector<pii> v[N];
int e[N];
int d[N];

int main () {
    int n, m;
    cin>>n>>m;
    for (int i = 0; i < m; i++) {
        int a, b, c;
        cin>>a>>b>>c;
        v[a].push_back({b, c});
        v[b].push_back({a, c});
    }
    for (int i = 1; i <= n; i++) {
        d[i] = 1000000000;
    }
    priority_queue<pii> q;
    q.push({0, 1});
    d[1] = 0;
    while (!q.empty()) {
        int i = q.top().second;
        int a = -q.top().first;
        q.pop();
        if (e[i]) continue;
        e[i] = 1;
        for (pii p : v[i]) {
            int j = p.first;
            int b = p.second;
            if (!e[j] && d[j] > a + b) {
                d[j] = a + b;
                q.push({-d[j], j});
            }
        }
    }
    int ans = 0;
    vector<int> s;
    s.push_back(n);
    e[n] = 2;
    for (int i = 0; i < s.size(); i++) {
        for (pii p : v[s[i]]) {
            if (d[p.first] + p.second == d[s[i]]) {
                ans += 2 * p.second;
                if (e[p.first] < 2) {
                    e[p.first] = 2;
                    s.push_back(p.first);
                }
            }
        }
    }
    cout<<ans<<endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED