typing_singh's blog

By typing_singh, history, 6 weeks ago, In English

https://cses.fi/problemset/task/1671/

I m getting tle in only 2 test cases of this problem. here's my code link--

https://ideone.com/SEcRXD

need help!!****

 
 
 
 
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6 weeks ago, # |
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Auto comment: topic has been updated by typing_singh (previous revision, new revision, compare).

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6 weeks ago, # |
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Your use of vis[] is not correct. if (!vis[v]&&dist[v] > dist[u] + weight)

Just remove it. It is enough to check if dist[v] can be relaxed. This is the case if a longer path is cheaper because sum of weights are less than a earlier, shorter path.

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    6 weeks ago, # ^ |
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    okay..but still giving tle. thanks for replying spookywooky

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      6 weeks ago, # ^ |
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      Sorry, I was wrong ;)

      You need a vis[] array here. But not inside the loop over the children. You should check vis[] array just after pop() from the queue.

      Since it is a priority_queue, the first time a node is popped from the queue the path is shortest, so all pops after the first one can be ignored.

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6 weeks ago, # |
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Just write this line "if(dist[u]<w)continue;" before the for loop in shortestpath function, here "w=pq.top().first".