MICEMAZE - Mice and Maze

Problem Link

#include <iostream>

#include <vector>

#include <queue>

#include <cstdio>

using namespace std;

const long INF = 9999999;

void dijkstra(int source, long dist[], vector< pair<int, long> > maze[])

{

priority_queue< pair<long, int> > pq;

dist[source] = 0;

pq.push(make_pair(0, source));

int neighbor;

long t;

while(!pq.empty())

{

int s = pq.top().second;

pq.pop();

for(int i = 0; i < maze[s].size(); i++)

{

neighbor = maze[s][i].first;

t = maze[s][i].second;

if(dist[neighbor] > dist[s] + t)

{

dist[neighbor] = dist[s] + t;

pq.push(make_pair(dist[neighbor], neighbor));

}

}

}

}

int main()

{

int n, exitCell, timer, edges, u, v, t;

int result = 0;

cin >> n >> exitCell >> timer >> edges;

vector< pair<int, long> > maze[n + 1];

long dist[n + 1];

for(int i = 0; i < edges; i++)

{

cin >> u >> v >> t;

maze[v].push_back(make_pair(u, t));

}

for(int i = 0; i < n + 1; i++)

{

dist[i] = INF;

}

dijkstra(exitCell, dist, maze);

for(int i = 1; i <= n; i++)

{

if(dist[i] <= timer)

{

result++;

}

}

cout << result << endl;

}