alamin_2014's blog

Why my dfs code is not working...?
By alamin_2014, history, 7 years ago, In English

simple dfs code.... why is it not working? please help input : 6 1 1 6 1 2 2 3 2 5 3 4 4 5 code : http://pastebin.com/EazYw5af my code run properly when I remove printf which is out of for loop in dfs function. If I write printf function... it does not work... strange..

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7 years ago, # |
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Because It's underfined behaviour. printf("%d %d\n",x,visited[G[x][k]]); At this line, k = G[x].size() because of end of loop.

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    7 years ago, # ^ |
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    It is not working when prinf is inside the loop outside the if statement. for(k=0; k<G[x].size(); k++) { if(visited[G[x][k]]==0) { visited[G[x][k]]=1;

    int v=G[x][k];
        //  cout<<v<<endl;
        dfs(v);
    }

    printf("%d %d\n",x,visited[G[x][k]]);
}
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      7 years ago, # ^ |
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      Make 'k' not global. Also don't use global variables at all.

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        7 years ago, # ^ |
        ← Rev. 2   Vote: I like it +13 Vote: I do not like it

        In real world programming using global variables is bad. But in competitive programming it usually improves working time of the solution and can be crucial. So I am not sure, if "don't use global variables at all" is good advice for competitive programming.

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