6，连续多位数的最大乘积

int test6(int num){ //最大连续几位，连续位数太多可以更改s的类型
    // char a[] = "7316717653133062491922511420752963450";
    char a[] ="1234560693212";
    int len = strlen(a);
    printf("%d
",len);
    int i,k;
    int j=1,s=0,sum;
    for(i=0; i<=len-num; i++){
        sum=1;
        for(k=0;k<num; k++){
            j = a[i+k]-0x30;
            sum *= j;
            if(j == 0){
                i+=k;
                break;
            }     
        }
        if(s<sum){
            s = sum;
        }
    }
    return s;
}