NYOJ1071

描述

判断：两个数x、y的正负性。

要求：不可以使用比较运算符，即"<",">","<=",">=","==","!="。

输入

有多组数据，每组数据占一行，每一行两个数x，y。
x、y保证在int范围内。

输出

每组数据输出占一行。
如果两个数是一正一负，输出"Signs are opposite"
如果是同为正或同为负，输出"Signs are not opposot"
如果无法确定，输出"Signs can't be sure"
输出不包括引号

样例输入

1 1
-1 1

样例输出

Signs are not opposot
Signs are opposite

#include<stdio.h> 
int main() {
	int x,y; 
	while(scanf("%d %d",&x,&y) == 2) {
		if(x*y>0) 
			printf("Signs are not opposot
"); 
			else if(x*y<0) 
				printf("Signs are opposite
");
					else printf("Signs can't be sure
"); 
	}
	return 0; 
}