计算器

#include<stdio.h>main(){    int data1,data2;    char op;    printf("Please enter an expression:");    scanf("%d%c%d",&data1,&op,&data2);    switch(op)    {        case'+':        printf("%d+%d=%d\n",data1,data2,data1+data2);        break;        case'-':            printf("%d-%d=%d\n",data1,data2,data1-data2);            break;        case'*':         printf("%d*%d=%d\n",data1,data2,data1*data2);         break;        case'/':            if(0==data2)                printf("Division by zero!\n");            else                 printf("%d/%d=%d\n",data1,data2,data1/data2);            break;        default:            printf("Invalid operator!\n");    }    return 0;}