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

Divide two integers.cpp

//
//  main.cpp
//  Divide_Two_Integers
//
//  Created by Zhoutuo Yang on 2/15/13.
//  Copyright (c) 2013 Zhoutuo Yang. All rights reserved.
//

#include <iostream>
using namespace std;

int divide(int dividend, int divisor) {
    // Start typing your C/C++ solution below
    // DO NOT write int main() function
    long tempDividend = abs((long)dividend);
    long tempDivisor = abs((long)divisor);
    
    if(tempDivisor > tempDividend) {
        return 0;
    }
    
    int sign = (dividend > 0) xor (divisor > 0) ? -1 : 1;
    
    if(tempDivisor == tempDividend) {
        return sign;
    }
    
    long quotient = 1;
    
    while(tempDividend >= tempDivisor) {
        quotient <<= 1;
        tempDivisor <<= 1;
    }
    
    quotient >>= 1;
    tempDivisor >>= 1;
    
    if(divisor > 0) {
        quotient += divide(tempDividend - tempDivisor, divisor);
    } else {
        quotient -= divide(tempDividend - tempDivisor, divisor);
    }
    
    return (int)(quotient * sign);
}

int main(int argc, const char * argv[])
{
    cout << divide(2147483647, 1) << endl;
}