10608 Why RE??

[cse.mehedi]

I can not understand why RE!
Please Any One Help Me!

Code: Select all


#include<stdio.h>
#define size 31000

bool adj_mat[size][size],visited[size];

 main()
{
   
    long n,node,con_no,a,b,i,dequeue,counter,tp,friends;
    scanf("%ld",&n);
    while(n--)
    {
        scanf("%ld %ld",&node,&con_no);
        if(con_no==0)
            printf("0\n");
        else
        {
        adj_mat[size][size]={0},visited[size]={0};
        long arr[size]={0};
        while(con_no>=1)
        {
            scanf("%ld %ld",&a,&b);
            if(adj_mat[b][a]==0)
            adj_mat[a][b]=1;
            con_no--;
        }
        friends=0;
        for(int k=1;k<=node;k++)
        {
            i=1,arr[1]=k,counter=1,tp=1;
            while(1)
            {
                dequeue=arr[i];
                if(dequeue==0) break;
                if(visited[i]==0)
                {
                    for(int j=1;j<=node;j++)
                    {
                        if(adj_mat[dequeue][j]==1)
                        {
                            counter++;
                            visited[j]=1;
                            arr[tp++]=j;
                        }
                    }
                    visited[i]=0;
                }
                if(friends<counter) friends=counter;
                i++;
            }
        }
       printf("%ld\n",friends); }
    }
    return 0;
}




[brianfry713]

if you declare a_mat of size c then you can only access up to c-1.

You're getting a seg fault during the sample input on line 16: a_mat[i][j]=0;

[cse.mehedi]

if you declare a_mat of size c then you can only access up to c-1.

You're getting a seg fault during the sample input on line 16: a_mat[i][j]=0;

I could not understand what should i do here "a_mat[i][j]=0".

[brianfry713]

You fixed the issue you were having before, trying to access beyond the limit of the array. Now I think you might be getting RE because you are trying put too much memory on the stack. Instead of declaring a huge local array long a_mat[c+1][c+1] where c can be up to 30000, and the values are only 0 or 1, try using a global bool array in c++.

This input causes your code to seg fault on my machine:

Code: Select all

1
30000 0

[cse.mehedi]

You fixed the issue you were having before, trying to access beyond the limit of the array. Now I think you might be getting RE because you are trying put too much memory on the stack. Instead of declaring a huge local array long a_mat[c+1][c+1] where c can be up to 30000, and the values are only 0 or 1, try using a global bool array in c++.

This input causes your code to seg fault on my machine:

Code: Select all

1
30000 0

Getting WA!

[brianfry713]

Input:

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1
2 1
1 2

AC Output:

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2

[cse.mehedi]

TLE!!!!!

[brianfry713]

Input:

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2
2 1
1 2
2 1
1 2

AC output:

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2
2

[cse.mehedi]

Input:

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2
2 1
1 2
2 1
1 2

AC output:

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2
2

TLE!!!!!!!!!

[brianfry713]

Input:

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2
2 1
1 2
3 1
2 3

AC Output:

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2
2

[cse.mehedi]

I modified my code but i am getting RE

[brianfry713]

This won't compile on my system.
You have these globals defined:
bool adj_mat[size][size],visited[size];
This isn't a declaration:
adj_mat[size][size]={0},visited[size]={0];
You can't access beyond adj_mat[size-1][size-1].
To clear an array using ={0} you must do it at declaration. You could try using memset() instead.