# Help in Dijkstra's Algorithm

I was testing my implementation of Dijkstra’s shortest path on HackerEarth but my code is giving WAs on very big test cases. Can someone figure out the reason…

Link of the problem (bottom of the hakerarth page): basic implementation problem

``````#include <iostream>
using namespace std;
#include<bits/stdc++.h>
typedef long long ll;
typedef pair<ll , ll> p;

int main() {

ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll n,m,x,y,w;
cin>>n>>m;
vector<ll> dist(n+1, 1e9);
priority_queue< p, vector <p> ,greater<p> > pq;

for(int i=0;i<m;i++)
{
cin>>x>>y>>w;
}
pq.push({0,1});
dist[1] = 0;

while (!pq.empty())
{
ll u = pq.top().second;
pq.pop();

{
ll v = i.first;
ll weight = i.second;

if(dist[v]>dist[u]+weight)
{
dist[v] = dist[u] + weight;
pq.push(make_pair(dist[v], v));
}

}

}
for (int i = 2; i <=n; ++i)
{
cout<<dist[i]<<" ";
}

}``````

The single input test case for the problem is incomplete. The first line in the data file specifies that N = 10,000 and M = 1,000,000. However, the file contains 999,201 lines only. This means that 800 edges are not included in the file.

1 Like