Divide two integers without using multiplication, division and mod operator.
If it is overflow, return MAX_INT.
2. Implementation
(1) 倍增法
class Solution {
public int divide(int dividend, int divisor) {
long a = Math.abs((long)dividend);
long b = Math.abs((long)divisor);
long res = 0;
while (a >= b) {
long temp = b;
int i = 0;
while (a >= temp) {
a -= temp;
temp <<= 1;
res += 1 << i;
++i;
}
}
if (dividend > 0 && divisor < 0 || dividend < 0 && divisor > 0) {
res = -res;
}
return res > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int)res;
}
}