设计一个C语言程序实现计算器功能包括加减乘除、小数、括号、取余

以下是一个简单的C语言程序实现计算器功能：

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#define MAX_EXPR_LEN 100

// 定义运算符栈结构体
typedef struct {
    char data[MAX_EXPR_LEN];
    int top;
} OperatorStack;

// 定义操作数栈结构体
typedef struct {
    double data[MAX_EXPR_LEN];
    int top;
} OperandStack;

// 初始化运算符栈
void initOperatorStack(OperatorStack *stack) {
    stack->top = -1;
}

// 初始化操作数栈
void initOperandStack(OperandStack *stack) {
    stack->top = -1;
}

// 判断是否为数字
int isNumber(char c) {
    return isdigit(c) || c == '.';
}

// 判断是否为运算符
int isOperator(char c) {
    return c == '+' || c == '-' || c == '*' || c == '/' || c == '%' || c == '(' || c == ')';
}

// 获取运算符优先级
int getPriority(char c) {
    switch (c) {
        case '+':
        case '-':
            return 1;
        case '*':
        case '/':
        case '%':
            return 2;
        default:
            return 0;
    }
}

// 将中缀表达式转换为后缀表达式
void infixToPostfix(char *infixExpr, char *postfixExpr) {
    OperatorStack operatorStack;
    initOperatorStack(&operatorStack);
    int i = 0, j = 0;
    while (infixExpr[i]) {
        if (isNumber(infixExpr[i])) {
            while (isNumber(infixExpr[i])) {
                postfixExpr[j++] = infixExpr[i++];
            }
            postfixExpr[j++] = ' ';
        } else if (isOperator(infixExpr[i])) {
            if (infixExpr[i] == '(') {
                operatorStack.data[++operatorStack.top] = infixExpr[i++];
            } else if (infixExpr[i] == ')') {
                while (operatorStack.data[operatorStack.top] != '(') {
                    postfixExpr[j++] = operatorStack.data[operatorStack.top--];
                    postfixExpr[j++] = ' ';
                }
                operatorStack.top--;
                i++;
            } else {
                while (operatorStack.top != -1 && operatorStack.data[operatorStack.top] != '('
                       && getPriority(operatorStack.data[operatorStack.top]) >= getPriority(infixExpr[i])) {
                    postfixExpr[j++] = operatorStack.data[operatorStack.top--];
                    postfixExpr[j++] = ' ';
                }
                operatorStack.data[++operatorStack.top] = infixExpr[i++];
            }
        } else {
            printf("Invalid character: %c\n", infixExpr[i]);
            exit(1);
        }
    }
    while (operatorStack.top != -1) {
        postfixExpr[j++] = operatorStack.data[operatorStack.top--];
        postfixExpr[j++] = ' ';
    }
    postfixExpr[j] = '\0';
}

// 计算后缀表达式
double calculatePostfix(char *postfixExpr) {
    OperandStack operandStack;
    initOperandStack(&operandStack);
    int i = 0;
    while (postfixExpr[i]) {
        if (isNumber(postfixExpr[i])) {
            char *start = postfixExpr + i;
            while (isNumber(postfixExpr[i])) {
                i++;
            }
            double num = atof(start);
            operandStack.data[++operandStack.top] = num;
        } else if (isOperator(postfixExpr[i])) {
            double b = operandStack.data[operandStack.top--];
            double a = operandStack.data[operandStack.top--];
            switch (postfixExpr[i]) {
                case '+':
                    operandStack.data[++operandStack.top] = a + b;
                    break;
                case '-':
                    operandStack.data[++operandStack.top] = a - b;
                    break;
                case '*':
                    operandStack.data[++operandStack.top] = a * b;
                    break;
                case '/':
                    operandStack.data[++operandStack.top] = a / b;
                    break;
                case '%':
                    operandStack.data[++operandStack.top] = (int)a % (int)b;
                    break;
            }
            i++;
        } else {
            printf("Invalid character: %c\n", postfixExpr[i]);
            exit(1);
        }
    }
    return operandStack.data[operandStack.top];
}

int main() {
    char infixExpr[MAX_EXPR_LEN], postfixExpr[MAX_EXPR_LEN];
    printf("Enter the infix expression: ");
    fgets(infixExpr, MAX_EXPR_LEN, stdin);
    infixToPostfix(infixExpr, postfixExpr);
    printf("The postfix expression is: %s\n", postfixExpr);
    printf("The result is: %lf\n", calculatePostfix(postfixExpr));
    return 0;
}

使用方法：在终端中运行程序，输入中缀表达式，程序将自动计算并输出结果。例如，输入`(2.5+3)*4-5%2`，程序将输出：

Enter the infix expression: (2.5+3)*4-5%2
The postfix expression is: 2.5 3 + 4 * 5 2 % - 
The result is: 16.000000