c - 对于较大的 n 值(大于 500000)，获取 SIGSEGV

Question

#include<stdio.h>
int l;
int check(int m[][l],int a,int r,int c,int e)
{
    int t,i,j;
    for(i=0;i<c;i++)
    {
        if(m[a][i]==e)
            return 1;
    }
    for(i=0;i<c;i++)
    {
        for(j=0;j<r;j++)
        {
            if(a!=j)
            {
                if(m[a][i]==m[j][i]&&m[a][i]!=-1)
                {
                    m[a][i]=-1;
                    return check(m,j,r,c,e);
                }
            }
        }
    }
    return 0;
}
int main()
{
    int t;
    int i,j;
    scanf("%d",&t);
    for(t;t>0;t--)
    {
        l=0;
        int n,e,a,b,x,y;
        scanf("%d%d%d%d",&n,&e,&a,&b);
        int m[e][n];
        l=n;
        for(i=0;i<e;i++)
        {
            for(j=0;j<n;j++)
            {
                m[i][j]=-1;
            }
        }
        for(i=0;i<e;i++)
        {
            scanf("%d%d",&x,&y);
            for(j=0;j<((n-y)/x)+1;j++)
            {
                m[i][y+(j*x)]=y+(j*x);
            }
        }
        int v,g=0;
        for(i=0;i<e;i++)
        {
            for(j=0;j<n;j++)
            {
                if(m[i][j]==a)
                {
                    v=check(m,i,e,n,b);
                    g++;
                    break;
                }
            }
        }
        if(v==1)
        {
            printf("It is possible to move the furniture.\n");
        }
        else if(v==0||g==0)
            printf("The furniture cannot be moved.\n");
    }
    return 0;
}

"I'm getting the correct answer for value of n<=50000, when i give more values i'm getting runtime error" "i have written a code for "http://www.spoj.pl/problems/SCRAPER/".. when i run it in ideone, i got the answers as "runtime error" for more 'n' values

Answer 1

您尝试分配的内存多于堆栈上的可用内存，这会导致堆栈溢出。通常，使用 malloc、calloc 或 realloc 动态分配这样的大数组要好得多。

检查这个问题:C: Array initialization segfaults depending on size and call to printf()