Lennot

input/code.cpp: In function 'int main()':
input/code.cpp:23:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     S(n); S(m);
         ^
input/code.cpp:23:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     S(n); S(m);
               ^
input/code.cpp:28:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         S(a); S(b); S(h);
             ^
input/code.cpp:28:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         S(a); S(b); S(h);
                   ^
input/code.cpp:28:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         S(a); S(b); S(h);
                         ^

#include <cstdio>
#include <iostream>
#include <set>
#include <vector>
#include <queue>
#include <map>

using namespace std;

#define REP(n) for(__typeof(n) _i=0; _i<(n); ++_i)
#define FOR(i,a,b) for(__typeof(b) i=a; i<b; ++i)
#define FORE(i,a,b) for(__typeof(b) i=a; i<=b; ++i)
#define S(x) scanf("%d", &(x))

typedef long long LL;

#define MAX(a,b) ((a)<(b) ? (b) : (a))

int main() {
    int n, m, a, b, h;
    priority_queue<pair<int,int>> pq;

    S(n); S(m);

    vector<vector<pair<int,int>>> to(n*2);

    REP(m) {
        S(a); S(b); S(h);
        to[a-1].push_back(make_pair(h, b-1+n)); // paid a to free b
        to[a-1+n].push_back(make_pair(0, b-1)); // free a to paid b
    }

    pq.push(make_pair(0,0)); // start at node 0

    set<int> seen;

    while(!pq.empty()) {
        auto p = pq.top(); pq.pop();
        int cost = p.first, node = p.second;

        if(seen.count(node)) continue; // visited
        //if(node<n)
        //    cout << "Paid node " << node+1 << " after " << -cost << endl;
        //else
        //    cout << "Free node " << node+1-n << " after " << -cost << endl;
        seen.insert(node);

        if(node+1 == n || node+1 == 2*n) {
            cout << -cost;
            break;
        }

        for(auto nd : to[node]) {
            //cout << "Can get to " << nd.second+1 << " with " << nd.first << endl;
            pq.push(make_pair(cost-nd.first, nd.second)); // negative to keep order
        }
    }

    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: WRONG ANSWER

Test 7

Group: 2

Verdict: WRONG ANSWER

Test 8

Group: 2

Verdict: WRONG ANSWER

Test 9

Group: 2

Verdict: WRONG ANSWER

Test 10

Group: 2

Verdict: WRONG ANSWER

Test 11

Group: 3

Verdict: WRONG ANSWER

Test 12

Group: 3

Verdict: WRONG ANSWER

Test 13

Group: 3

Verdict: WRONG ANSWER

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: ACCEPTED