Reverse Integer

06/23/2016 Math

Question

Reverse digits of an integer.

Examples:

x = 123, return 321
x = -123, return -321

Solution

Result: Accepted Time: 8ms

Here should be some explanations.

int reverse(int x) {
    int flag = 1;
    const int limit = 0x7fffffff / 10 ;
    int ans=0,last = 0;
    if(x < 0)
    {
        flag = -1;
        if(x == 0x80000000)
            return 0;
        x = -x;
    }
    while(x)
    {
        if(last > limit )
            return 0;
        ans= ans*10 + x%10;
        x/=10;
        last = ans;
    }
    return ans*flag;
}

Complexity Analytics

  • Time Complexity:
  • Space Complexity: