Thread: SIGSEGV fault

I'm getting runtime error (SIGSEGV) for the following code:

Code:

#include<stdio.h>
#include <string.h>
   
int lcs( char *A, char *B, int m, int n ){   
int L[m+1][n+1];   
int i, j;     
for (i=0; i<=m; i++)   {     
for (j=0; j<=n; j++)     {       
if (i == 0 || j == 0)        
      L[i][j] = 0;       
 else if (A[i-1] == B[j-1])         
      L[i][j] = L[i-1][j-1] + 1;        
 else         
      L[i][j] = max(L[i-1][j], L[i][j-1]);     
    }   
}    
return L[m][n];
}  

int max(int p, int r){    
return (p > r)? p : r;
} 

int main(){    
int t;    
scanf("%d", &t);    
while(t--){  
char X[25005];  char Y[25005];  
scanf("%s%s", X,Y);   
int len1 = strlen(X);  
int len2 = strlen(Y);  
int z = lcs(X,Y,len1,len2);    
if(z == len1 || z == len2)printf("YES\n");    
else printf("NO\n");    
}  
return 0; 
}

What can be the reason?

Code:

$ gcc -g -Wall foo.c
foo.c: In function ‘lcs’:
foo.c:14:7: warning: implicit declaration of function ‘max’ [-Wimplicit-function-declaration]
$ ./a.out 
1
hello
world
NO
$ ./a.out 
1
hello
hello
YES

You need to provide a crashing test case if you want more help.