使用命令行界面和malloc创建计算器

int add(int a, int b) {
    return a + b;
}

int subtract(int a, int b) {
    return a - b;
}

int multiply(int a, int b) {
    return a * b;
}

int divide(int a, int b) {
    return a / b;
}

#include <stdio.h>

int main() {
    int a, b;
    char operator;

    printf("请输入第一个操作数：");
    scanf("%d", &a);

    printf("请输入操作符：");
    scanf(" %c", &operator);

    printf("请输入第二个操作数：");
    scanf("%d", &b);

    int result;

    switch (operator) {
        case '+':
            result = add(a, b);
            break;
        case '-':
            result = subtract(a, b);
            break;
        case '*':
            result = multiply(a, b);
            break;
        case '/':
            result = divide(a, b);
            break;
        default:
            printf("无效的操作符\n");
            return 1;
    }

    printf("计算结果：%d\n", result);

    return 0;
}

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

typedef struct {
    int (*add)(int, int);
    int (*subtract)(int, int);
    int (*multiply)(int, int);
    int (*divide)(int, int);
} Calculator;

Calculator* createCalculator() {
    Calculator* calculator = (Calculator*) malloc(sizeof(Calculator));
    calculator->add = add;
    calculator->subtract = subtract;
    calculator->multiply = multiply;
    calculator->divide = divide;
    return calculator;
}

void destroyCalculator(Calculator* calculator) {
    free(calculator);
}

int main() {
    Calculator* calculator = createCalculator();

    int a, b;
    char operator;

    printf("请输入第一个操作数：");
    scanf("%d", &a);

    printf("请输入操作符：");
    scanf(" %c", &operator);

    printf("请输入第二个操作数：");
    scanf("%d", &b);

    int result;

    switch (operator) {
        case '+':
            result = calculator->add(a, b);
            break;
        case '-':
            result = calculator->subtract(a, b);
            break;
        case '*':
            result = calculator->multiply(a, b);
            break;
        case '/':
            result = calculator->divide(a, b);
            break;
        default:
            printf("无效的操作符\n");
            destroyCalculator(calculator);
            return 1;
    }

    printf("计算结果：%d\n", result);

    destroyCalculator(calculator);

    return 0;
}