题解 | #简单计算器#

#include<stdio.h>
int main()
{
	double n1 = 0.0; 
	double n2 = 0.0;  
	char opt = '0'; 
	while (scanf("%lf %c %lf", &n1, &opt, &n2) != EOF)
	{
		switch (opt)
		{
		case '+':
			printf("%.4lf+%.4lf=%.4lf", n1 ,n2 ,n1+n2); 
			break; 
		case'-':
			printf("%.4lf-%.4lf=%.4lf", n1 , n2,n1-n2);
			break;  
		case'*':
			printf("%.4lf*%.4lf=%.4lf", n1 ,n2,n1*n2);
			break; 
		case'/':
			if (n2 == 0.0)
			{
				printf("Wrong!Division by zero!\n");
				break; 
			}
			else
			{
				printf("%.4lf/%.4lf=%.4lf", n1 ,n2 , n1/n2);
				break; 
			}
		default:
			printf("Invalid operation!\n"); 
			break; 
		}
	}
	return 0; 
}