请用c语言写一个简单的计算器

Sure, I can help you with that! Here's a simple calculator program in C:

#include <stdio.h>

int main()
{
    char operator;
    double num1, num2, result;

    printf("Enter an operator (+, -, *, /): ");
    scanf("%c", &operator);

    printf("Enter two numbers: ");
    scanf("%lf %lf", &num1, &num2);

    switch(operator)
    {
        case '+':
            result = num1 + num2;
            break;
        case '-':
            result = num1 - num2;
            break;
        case '*':
            result = num1 * num2;
            break;
        case '/':
            result = num1 / num2;
            break;
        default:
            printf("Invalid operator\n");
            return 1;
    }

    printf("Result: %.2lf\n", result);

    return 0;
}

You can copy and paste this code into your favorite C compiler and run it. When prompted, enter the operator (+, -, *, or /) and the two numbers you want to perform the calculation on. The program will then display the result of the operation. Enjoy!