题解 | #简单计算器#

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main() {
  	//四舍五入用double类型
    double Num1 = 0, Num2 = 0;
    char operation = '0';
  	//使用double类型需要使用%lf
    scanf("%lf%c%lf", &Num1, &operation, &Num2);
    if (operation == '+')
        printf("%.4lf%c%.4lf=%.4lf\n", Num1, operation, Num2, Num1 + Num2);
    else if (operation == '-')
        printf("%.4lf%c%.4lf=%.4lf\n", Num1, operation, Num2, Num1 - Num2);
    else if (operation == '*')
        printf("%.4lf%c%.4lf=%.4lf\n", Num1, operation, Num2, Num1 * Num2);
    else if (operation == '/') {
	  	//除号需要判断数值是否合理
        if (Num2 == 0)
            printf("Wrong!Division by zero!\n");
        else
            printf("%.4lf%c%.4lf=%.4lf\n", Num1, operation, Num2, Num1 / Num2);
    } else
	  	//不属于四则运算符的需要剔除
        printf("Invalid operation!\n");
    return 0;
}