#include<stdio.h>void print(void){printf("*************************\n");printf("*****1:add 2:sub*******\n");printf("*****3:mul 4:div*******\n");printf("*************************\n");}int add(int x,int y)//加法{return x+y;}int sub(int x,int y)//减法{return x-y;}int mul(int x,int y)//乘法{return x*y;}int div(int x,int y)//除法{return x/y;}int main(){int a,b;int input=0;print();printf("请选择:\n");scanf("%d",&input);if((input>0)&&(input<5)){printf("请输入两个操作数:\n");scanf("%d %d",&a,&b);}switch(input){case 1:printf("结果是：%d\n",add(a,b));break;case 2:printf("结果是：%d\n",sub(a,b));break;case 3:printf("结果是：%d\n",mul(a,b));break;case 4:printf("结果是：%d\n",div(a,b));break;default: break;}return 0;}
，放下一处烦恼，收获一个惊喜；放下一种偏见，收获一种幸福；
