I have been coding on leetcode to reverse the number in a 32-bit environment. This error is popping up for test case where x=-2147483648. I have seen other solutions for the same problem and i understand them but i just want to know why this code is wrong..

int reverse(int x) {
    if (x==0){
        return 0;
    }
    bool n = false;

    if (x<0){
        x = -x;    
        n = true;       
    }

    long num = 0,count =0;
    while (x>0){
        int rem;
        rem = x%10;
        x = x/10;
        if ( (num*10) > (pow(2,31)-1) || (num*10) < -pow(2,31)){
            return 0;
        }
        num = num*10 + rem;
        
    }
    
    if(n==true){
        num = -num;
    }

    return num;
}

this is the code i tried