Divide two integers without using multiplication, division and mod operator.

If it is overflow, return MAX_INT.

Solution:

1 public class Solution { 2     public int divide(int dividend, int divisor) { 3         if (divisor==0) return Integer.MAX_VALUE; 4         if (dividend==0) return 0; 5         if (divisor==1) return dividend; 6         if (dividend==Integer.MIN_VALUE && divisor==-1) return Integer.MAX_VALUE; 7  8         boolean neg = false; 9         //change to all negtive number.10         if (dividend>0){11             dividend = -dividend;12             neg = !neg;13         }14         if (divisor>0){15             divisor = - divisor;16             neg = !neg;17         }18 19         int minDivisor = Integer.MIN_VALUE >> 1;20         int cur = divisor;21         int val = 1;22         while (cur>=minDivisor && cur>dividend){23             cur <<= 1;24             val <<= 1;25         }26 27         int res = 0;28         while (dividend<=divisor){29             while (cur
     
      >= 1;31                 val >>= 1;32             }33             dividend -= cur;34             res += val;35         }36 37         if (neg) return -res;38         else return res;39     }40 }