1 class Solution {
2 public int divide(int dividend, int divisor) {
3 long count = 0;
4 if(dividend == 0) return 0;
5 //divisor和dividend都要变成正数和long再进行处理
6 if((dividend > 0 && divisor >0) || (dividend < 0 && divisor < 0)) {
7 long ldivisor = Math.abs((long)divisor);
8 long ldividend = Math.abs((long)dividend);
9 count = longdivide(ldividend, ldivisor);
10
11 }else {
12 long ldivisor = Math.abs((long)divisor);
13 long ldividend = Math.abs((long)dividend);
14 count = -longdivide(ldividend, ldivisor);
15 }
16
17 //overflow处理
18 if(count > 0) {
19 return (int) (count > Integer.MAX_VALUE ? Integer.MAX_VALUE : count);
20 }else {
21 return (int) (count < Integer.MIN_VALUE ? Integer.MIN_VALUE : count);
22 }
23
24
25 }
26
27 //类似binary search
28 public long longdivide(long dividend, long divisor) {
29 if(dividend < divisor) return 0;
30 long multiple = 1;
31 long sum = divisor;
32 while((sum + sum) < dividend) {
33 sum += sum;
34 multiple +=multiple;
35 }
36 return multiple + longdivide(dividend - sum, divisor);
37
38 }
39 }
