solve.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

int getSign(long a, long b)
{
	if ((a < 0 && b > 0) || (a > 0 && b < 0))
		return 1;
	return 0;
}
long labs(long a)
{
	return a >= 0 ? a : -a;
}
int divide(int dividend, int divisor)
{
	if (divisor == 0) {  // 除数为0
		return dividend >= 0 ? INT_MAX : INT_MIN;
	}
	long n = dividend; // 防止溢出，当其中一个=INT_MIN
	long m = divisor;
	int sign = getSign(n, m); // 保存结果的符号
	n = labs(n);
	m = labs(m);
	long ans = 0;
	long a; // 防止 a << 1溢出
	long k;
	while (n >= m) {
		a = m, k = 1;
		while (n > (a << 1)) {
			a <<= 1;
			k <<= 1;
		}
		n -= a;
		ans += k;
	}
	ans = sign ? -ans : ans;
	if (ans > INT_MAX)
		return INT_MAX;
	if (ans < INT_MIN)
		return INT_MIN;
	return ans;
}
int main(int argc, char **argv)
{
	int a,b;
	while (scanf("%d%d", &a, &b) != EOF)
		printf("%d\n", divide(a, b));
	return 0;
}