code got timed out...please suggest improvements for a more efficient algorithm...thanks in advance! :)

int gcd(int a,int b){

if(a>b && b!=0) return gcd(a%b,b); if(b>a && a!=0) return gcd(a,b%a);

if(a==0)
    return b;
else return a;

} int main(){ int n; int m; int q; scanf("%d %d %d",&n,&m,&q); int *a = malloc(sizeof(int) * n); for(int a_i = 0; a_i < n; a_i++){ scanf("%d",&a[a_i]); } int *b = malloc(sizeof(int) * m); for(int b_i = 0; b_i < m; b_i++){ scanf("%d",&b[b_i]); } for(int a0 = 0; a0 < q; a0++){ int r1; int c1; int r2; int c2; scanf("%d %d %d %d",&r1,&c1,&r2,&c2);

    int matrix[n][m];

    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++)
        matrix[i][j]=gcd(a[i],b[j]);



        int distinct=1;

    int arr[(r2-r1+1)*(c2-c1+1)];

    int k=0;

    for(int i=r1;i<=r2;i++){
        for(int j=c1;j<=c2;j++){

         arr[k]=matrix[i][j]-matrix[r1][c1];
            k++;
        }

    }


   int j;


     for(int i=1;i<k;i++){
        int temp=arr[i];
        j=i-1;
        while(j>=0&&temp<arr[j]){
            arr[j+1]=arr[j];
            j--;
            arr[j+1]=temp;

        }
    }



     int max=0;
    distinct=1;
    for(int i=0;i<k;i++)
        if(arr[i]>max){
        max=arr[i];
        distinct++;

    }
    int minimum=0;
    for(int i=0;i<k;i++)
        if(arr[i]<minimum){
        minimum=arr[i];
        distinct++;
    }

     printf("%d\n",distinct);

   }
return 0;

}