用c语言数据结构编写：简易计算器

好的，以下是一个简单的用 C 语言数据结构编写的计算器：

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

struct Stack {
    int top;
    int capacity;
    int* array;
};

// 创建一个栈
struct Stack* createStack(int capacity) {
    struct Stack* stack = (struct Stack*) malloc(sizeof(struct Stack));
    stack->capacity = capacity;
    stack->top = -1;
    stack->array = (int*) malloc(stack->capacity * sizeof(int));
    return stack;
}

// 判断栈是否为空
int isEmpty(struct Stack* stack) {
    return stack->top == -1;
}

// 判断栈是否已满
int isFull(struct Stack* stack) {
    return stack->top == stack->capacity - 1;
}

// 入栈操作
void push(struct Stack* stack, int item) {
    if (isFull(stack))
        return;
    stack->array[++stack->top] = item;
}

// 出栈操作
int pop(struct Stack* stack) {
    if (isEmpty(stack))
        return -1;
    return stack->array[stack->top--];
}

// 获取栈顶元素
int peek(struct Stack* stack) {
    if (isEmpty(stack))
        return -1;
    return stack->array[stack->top];
}

// 判断字符是否为操作符
int isOperator(char ch) {
    return ch == '+' || ch == '-' || ch == '*' || ch == '/';
}

// 计算表达式
int evaluate(char* expression) {
    struct Stack* stack = createStack(strlen(expression));
    int i, operand1, operand2;
    for (i = 0; expression[i]; i++) {
        if (isdigit(expression[i])) {
            push(stack, expression[i] - '0');
        } 
        else if (isOperator(expression[i])) {
            operand2 = pop(stack);
            operand1 = pop(stack);
            switch (expression[i]) {
                case '+': push(stack, operand1 + operand2); break;
                case '-': push(stack, operand1 - operand2); break;
                case '*': push(stack, operand1 * operand2); break;
                case '/': push(stack, operand1 / operand2); break;
            }
        }
    }
    return pop(stack);
}

int main() {
    char expression[100];
    printf("请输入一个表达式：");
    scanf("%s", expression);
    int result = evaluate(expression);
    printf("计算结果是：%d\n", result);
    return 0;
}

这个计算器支持四则运算，可以输入包含数字和运算符的表达式，例如 "3+4*2-1"，然后计算出结果并输出。