Divide Two Integers

 1 class Solution {
 2 public:
 3     int divide( int dividend, int divisor ) {
 4         if( divisor == 0 ) { return -1; }
 5         if( dividend == 0 ) { return 0; }
 6         if( divisor == INT_MIN ) { return dividend == INT_MIN; }
 7         int ret = 0, sign = dividend > 0;
 8         if( divisor < 0 ) { sign = !sign; }
 9         if( dividend == INT_MIN ) {
10             dividend += abs( divisor );
11             ret = 1;
12         }
13         dividend = abs( dividend );
14         divisor = abs( divisor );
15         int num = 0;
16         while( dividend - (divisor<<num) >= (divisor<<num) ) { ++num; }
17         while( num >= 0 ) {
18             if( dividend >= (divisor<<num) ) {
19                 dividend -= (divisor<<num);
20                 ret += (1<<num);
21             }
22             --num;
23         }
24         return sign ? ret : -ret;
25     }
26 };