Submission #9196

#	Time	Username	Problem	Language	Result	Execution time	Memory
9196		roott76	Your life (kriii2_Y)	C++98	4 / 4	220 ms	8532 KiB

Y

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

int N;
vector<pair<int, int> > adj[100001];

vector<int> dijkstra(int src)
{
    vector<int> dist(N, 999999999);
    dist[src] = 0;
    priority_queue<pair<int, int> > pq;
    pq.push(make_pair(0, src));
    while(!pq.empty())
    {
        int cost = -pq.top().first;
        int here = pq.top().second;
        pq.pop();
        
        if(dist[here] < cost) continue;
        
        for(int i=0; i<adj[here].size(); i++)
        {
            int there = adj[here][i].first;
            int nextDist = cost + adj[here][i].second;
            
            if(dist[there] > nextDist)
            {
                dist[there] = nextDist;
                pq.push(make_pair(-nextDist, there));
            }
        }
    }
    
    return dist;
}

int main()
{
    int M;
    cin >> N >> M;
    
    for(int i=0; i<M; i++)
    {
        int a, b, c = 1;
        cin >> a >> b;
        adj[a-1].push_back(make_pair(b-1, c));
    }
    
    vector<int> Dist = dijkstra(0);
    if(N == 1) cout << "0";
    else if(Dist[N-1] == 999999999) cout << "-1";
    else cout << Dist[N-1];
    cout << endl;
}

• Subtask 1: 1 / 1
• Subtask 2: 3 / 3