C语言程序优化：实现任意输入顺序的三数大小排序输出

你的代码存在几个关键问题，导致只能处理特定顺序的输入：

• 变量初始化不合理：highestNumber、middleNumber、lowestNumber初始为0，若输入全负数会完全失效
• 条件判断逻辑有漏洞：首次输入时middleNumber和lowestNumber都是0，后续判断无法正确赋值
• 变量名拼写错误：printf里的highiestNumber是笔误，应为highestNumber

下面提供两种可靠的修改方案：

方案1：数组存储后排序（简单直观） #

把输入的三个数存入数组，通过简单排序后输出，逻辑清晰不易出错：

#include <stdio.h>

int main() {
    int nums[3];
    
    // 输入三个数（提示改为1、2、3，更符合用户习惯）
    for (int i = 0; i < 3; i++) {
        printf("Type the %d number: ", i + 1);
        scanf("%d", &nums[i]);
    }
    
    // 针对三个数的简化冒泡排序
    int temp;
    if (nums[0] > nums[1]) {
        temp = nums[0];
        nums[0] = nums[1];
        nums[1] = temp;
    }
    if (nums[0] > nums[2]) {
        temp = nums[0];
        nums[0] = nums[2];
        nums[2] = temp;
    }
    if (nums[1] > nums[2]) {
        temp = nums[1];
        nums[1] = nums[2];
        nums[2] = temp;
    }
    
    // 输出排序后的结果
    printf("The highest number is: %d, the middle number is: %d and the lowest number is %d.\n", nums[2], nums[1], nums[0]);
    
    return 0;
}

方案2：动态维护三个值（无需数组） #

每次输入后直接更新最大值、中间值、最小值，无需额外数组存储：

#include <stdio.h>

int main() {
    int num, highest, middle, lowest;
    
    // 输入第一个数，初始化三个变量
    printf("Type the 1st number: ");
    scanf("%d", &num);
    highest = middle = lowest = num;
    
    // 处理第二个数
    printf("Type the 2nd number: ");
    scanf("%d", &num);
    if (num > highest) {
        lowest = middle;
        middle = highest;
        highest = num;
    } else if (num < lowest) {
        highest = middle;
        middle = lowest;
        lowest = num;
    } else {
        middle = num;
    }
    
    // 处理第三个数
    printf("Type the 3rd number: ");
    scanf("%d", &num);
    if (num > highest) {
        lowest = middle;
        middle = highest;
        highest = num;
    } else if (num < lowest) {
        highest = middle;
        middle = lowest;
        lowest = num;
    } else {
        if (num > middle) {
            lowest = middle;
            middle = num;
        } else if (num < middle) {
            highest = middle;
            middle = num;
        }
    }
    
    printf("The highest number is: %d, the middle number is: %d and the lowest number is %d.\n", highest, middle, lowest);
    
    return 0;
}

两种方案都能处理任意输入顺序的三个不同数字，完全满足需求。

内容的提问来源于stack exchange，提问作者user23711636