Lennot

#include <iostream>
#include <stdio.h>
#include <vector>
#include <deque>
#include <string>

using namespace std;

int main(int argc, char* argv[])
{
	ios_base::sync_with_stdio(0);
	int cities, flights;
	cin >> cities >> flights;
	vector<vector<pair<int,int> > > cityList(cities);

	for (int i = 0; i < flights; i++){
		int from,to,price;
		cin >> from;
		cin >> to;
		cin >> price;
		from--;
		to--;
		cityList[from].push_back(make_pair(to,price));
	}
	vector<int> z;
	vector<pair<int,int> > price(cities, make_pair(-1,-1));
	price[0] = make_pair(-1, 0);
	z.push_back(0);
	for (unsigned int i = 0; i < z.size(); i++) {
		for (unsigned int j = 0; j < cityList[z[i]].size(); j++) { 
			int u = cityList[z[i]][j].first;
			bool b = false;
			if ((price[u].first == -1 || price[u].first > price[z[i]].second + cityList[z[i]][j].second) && price[z[i]].second != -1){
				price[u].first = price[z[i]].second + cityList[z[i]][j].second;
				b = true;
			}
			if ((price[u].second == -1 || price[u].second > price[z[i]].first) && price[z[i]].first != -1){
				price[u].second = price[z[i]].first;
				b = true;
			}
			if (b)
				z.push_back(u);
		}
	}
	if (price[cities - 1].first != -1){
		if (price[cities - 1].second != -1){
			if (price[cities - 1].first > price[cities - 1].second)
				cout << price[cities - 1].second;
			else
				cout << price[cities - 1].first;
		}
		else
			cout << price[cities - 1].first;
	}
	else
		cout << price[cities - 1].second;
	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