7. Reverse Integer

Reverse digits of an Integer.

Example1 : x = 123 , return 321

Example2 : x = -123 , return -321

int reverse(int x) {
    
}

My Solution

  • just % and * with 10
int reverse(int x) {
    int digit=10;
    int number=x;
    int returnNumber = 0;

    while (number != 0 ) {
        if (returnNumber * 10/10 != returnNumber)
            return 0;
        returnNumber *=10;
        returnNumber += number%10;
        number = number/10;
    }

    return returnNumber;
    
}

I wanted to change a part of the above source.

int reverse(int x) {
    int digit=10;
    long long int number=x;
    long long int returnNumber = 0;

    while (number != 0 ) {
        if ((returnNumber * 10 > INT_MAX) || (returnNumber * 10 < INT_MIN))
            return 0;
        returnNumber *=10;
        returnNumber += number%10;
        number = number/10;
    }
    return returnNumber;
}

Reference

on C++, headerfile including INT_MIN, INT_MAX is