寻找数组最小值下标的函数中有一个语句不知道为什么无效(语言-c++)

Question

正在学C语言，做书上的练习题，用的vs2022，要找出数组最大，最小值下标，然后卡在最小值下标这了。函数SUBSCRIPT_min的返回值一直都是0，在SUBSCRIPT_min函数内用printf直接输出sub也一直是0，大概是sub = i + 1这个语句没有起效果，但不知道是为什么。

#include<stdio.h>
void MAX_array(int arr[5]);
void MIN_array(int arr[5]);
int SUBSCRIPT_min(int arr[5]);
int SUBSCRIPT_max(int arr[5]);
int main()
{
    int arr[5] = { 1,2,3,4,5 };
    int i,s=0;
    printf_s("Enter five number,please.\n");
    for (i = 0; i <5 ; i++)
    {
        scanf_s("%d", &arr[i]);
    }
    printf_s("Which number do you want,min or max?\n1)min      2)max(0 to quit)\n");
    scanf_s("%d", &s);
    while (s != 0)
    {
        switch (s)
        {
        case 1:MIN_array(arr);
            printf_s("The subscript of the minimum is %d.\n", SUBSCRIPT_min(arr));
            break;
        case 2:MAX_array(arr);
            break;
        case 3:
        default:printf_s("Error!\n");
            break;
        }
        printf("Please enter 1 or 2.(0 to quit)\n");
        scanf_s("%d", &s);
    }
}
void MAX_array(int arr[5])
{
    int i,max=0;
    for ( i = 0; i < 4; i++)
    {
        if (arr[0]<arr[i+1])
        {
            arr[0] = arr[i + 1];
        }
    }
    max = arr[0];
    printf_s("The maximum is %d.\n", max);
}
void MIN_array(int arr[5])
{
    int i, min = 0;
    for (i = 0; i < 4; i++)
    {
        if (arr[0] > arr[i + 1])
        {
            arr[0] = arr[i + 1];
        }
    }
    min = arr[0];
    printf_s("The minimum is %d.\n", min);
}
int SUBSCRIPT_min(int arr[5])
{
    int i, sub=0;
    for (i = 0; i < 4; i++)
    {
        if (arr[0] > arr[i + 1])
        {
            arr[0] = arr[i + 1];
            sub = i + 1;
        }
    }
    return sub;
}

Answer 1

回答：你这边的min函数修改了原来的数组，这边给出测试结果，写的函数没啥问题，但在下标会溢出，已修改

#include<stdio.h>

void MAX_array(int arr[5]);
void MIN_array(int arr[5]);
int SUBSCRIPT_min(int arr[5]);
int SUBSCRIPT_max(int arr[5]);

int main()
{
    int arr[5] = { 1,2,3,4,5 };
    int i,s=0;
    printf_s("Enter five number,please.\n");
    for (i = 0; i <5 ; i++)
    {
        scanf_s("%d", &arr[i]);
    }
    printf_s("Which number do you want,min or max?\n1)min      2)max(0 to quit)\n");
    scanf_s("%d", &s);
    while (s != 0)
    {
        switch (s)
        {
        case 1:MIN_array(arr);
            printf_s("The subscript of the minimum is %d.\n", SUBSCRIPT_min(arr));
            break;
        case 2:MAX_array(arr);
            break;
        case 3:
        default:printf_s("Error!\n");
            break;
        }
        printf("Please enter 1 or 2.(0 to quit)\n");
        scanf_s("%d", &s);
    }
}

void MAX_array(int arr[5]){
    
}
void MIN_array(int arr[5]){
    
}

/* 
void MAX_array(int arr[5])
{
    int i,max=0;
    for ( i = 0; i < 4; i++)
    {
        if (arr[0]<arr[i+1])
        {
            arr[0] = arr[i + 1];
        }
    }
    max = arr[0];
    printf_s("The maximum is %d.\n", max);
}

void MIN_array(int arr[5])
{
    int i, min = 0;
    for (i = 0; i < 4; i++)
    {
        if (arr[0] > arr[i + 1])
        {
            arr[0] = arr[i + 1];
        }
    }
    min = arr[0];
    printf_s("The minimum is %d.\n", min);
}
*/

int SUBSCRIPT_min(int arr[5])
{
    int i, sub=0;
    for (i = 0; i < 4; i++)
    {
        if (arr[0] > arr[i])  //原来的i+1会溢出 
        {
            arr[0] = arr[i];
            sub = i + 1;
        }
    }
    return sub;
}