/*计算器*/
#include<stdio.h>
int add(int x,int y){
	return (x+y);
} 

int sub(int x,int y){
	return (x-y);
}

int mul(int x,int y){
	return (x*y);
}

int div(int x,int y){
	return (x/y);
}

int main(){
	int x,y;
	int answer=0; //刚开始胡乱写的，后面用户输入就被覆盖了 
	int input=1; //input是对加减乘除的选择 
	int(*ans[5])(int x,int y)={0,add,sub,mul,div};
	printf("*********请选择*********\n");
	printf("*****1.add    2.sub*****\n");
	printf("*****3.mul    4.div*****\n");
	printf("************************\n");
	scanf("%d",&input);
	if(input<=4&&input>=1){
	printf("请输入您要计算的两个数："); 
	scanf("%d %d",&x,&y);
	answer=(*ans[input])(x,y);}
	else printf("输入错误！");
	printf("answer=%d",answer); 
	return 0;
}