c - 如何在已修改的函数外部打印数组值

Question

void sort(int values[], int n);  

void modify_all_aray_values_to_0(int value[], int array_size);

int main(void)
{
    int aray[] = {4,2,56,2,1,7,20,9,3,5,6,4,3,2,44,57};
    int size_of_aray = sizeof(aray)/sizeof(aray[0]);
    sort(aray, size_of_aray);
    printf("\n");
}

void sort(int values[], int n)
{
    // TODO: implement a sorting algorithm
    int temporary;
    //assumes temporary array size will not exceed 1000
    int temporary_array[1000];
    int size_of_tmp_array = sizeof(temporary_array)/sizeof(temporary_array[0]);
    //set all values in temporary array to 0
    modify_all_aray_values_to_0(temporary_array, size_of_tmp_array);
    for(int i = 0; i < n; i++)
    {
        //store the values of values[] i'th in temporary variable
        //at this stage, temporary = 4, because first element in values[] is 4
        temporary = values[i];
        //store result of temporary_array[4]+1 in temporary_array[4]
        //at this stage temporary_array[4],s values is 0
        //when i assigned it, it gets the value (0) and increment it with 1
        //this means so far i have seen value 4 once in values[]
        /*so if this loops again and it found value 4, it will
        modify and increment temporary_array value to 2*/
        temporary_array[temporary] = temporary_array[temporary]+1;
        //so at the end of the loop
        //temporary_array[1] = 1
        //temporary_array[2] = 3
        //temporary_array[3] = 2
        //temporary_array[4] = 2 and so on...
    }
    int tu;
    //print all values in values[] before it get modified
    for(int i = 0; i < n; i++)
    {
        printf("%i-", values[i]);
    }
    printf("\n");
    //assumes it wont loop more than 100 times
    for(int i = 0; i < 100; i++)
    {
        if(temporary_array[i] > 0)
        {
            for(tu = 0; 0 < temporary_array[i]; tu++ )
            {
                //modify valeus[] by assigning i'th value
                //at this stage if when temporary_array[1] is greater than 0
                //store 1 in values[0]
                values[tu] = i;
                //immediately decrease temporary_array[1] by 1
                //now temporary_array[1] is now 0
                //next time the loop will check if its greater than 0
                //if so it will modify values[] and store the value
                //else it wont bother and that means 1 doesnt appear in array again
                temporary_array[i] = temporary_array[i]-1;
                //print values[0] inside loop after modification
                printf("%i,", values[tu]);
                //printed 1
                //will print 1,2,2,2,3,3... and so on after compilation
            }
        }
    }
    printf("\n");
    for(int i = 0; i < n; i++)
    {
        //print values[0] outside the previous loop
        printf("%i-", values[i]);
        //this time around it printed 57 instead of 1
        //prints 57-4-2-2-1-7-20... and so on
        //what could have happend?
    }
    printf("\n");
    return;
}

void modify_all_aray_values_to_0(int value[], int array_size)
{
    for(int i = 0; i < array_size; i++)
    {
        value[i] = 0;
    }
}

请帮我解决这个问题。 我之前已经发布过这个问题，但它不好理解，所以我决定删除该问题并研究用户评论，只是为了从我的错误中吸取教训，以便我能够提出我们能够理解的问题。

我确实练习了代码格式，感谢上帝，现在它比我发布的上一篇文章更好了。

Answer 1

我能够发现您的代码存在很多问题。首先，你一定要阅读How to Ask 。给你几点:

1. 不要在代码中添加太多注释，这会让人难以理解
2. 使用常见概念的名称，以便其他人轻松理解您在做什么。就像这里，从它的外观来看，您正在尝试实现 Counting Sort

至于代码，您遇到的主要错误是由于此代码块造成的

for(int i = 0; i < 100; i++)
    if(temporary_array[i] > 0)//If the count of a number is > 0
        for(tu = 0; 0 < temporary_array[i]; tu++ ){ //<- ERROR HERE 
            values[tu] = i;
            temporary_array[i] = temporary_array[i]-1;
            printf("%i,", values[tu]);
        }

问题是您每次都将 values[tu] 设置为 temporary_array 中新发现的非零项。因此，首先，您创建 values[0]=1，然后再次更改 values[0]=2 等等...

我并不是指出问题的确切解决方案或者你为什么会遇到这个问题。因为我们鼓励您自己解决这个问题。因此，继续查看该代码块并尝试修复它。如果还有更多问题，可以询问:)

PS:这是我对您的代码进行编辑的版本，这使我更容易解释

#include <stdio.h>

void sort(int values[], int n);  

void modify_all_aray_values_to_0(int value[], int array_size);

int main(void){
    int aray[] = {4,2,56,2,1,7,20,9,3,5,6,4,3,2,44,57};
    int size_of_aray = sizeof(aray)/sizeof(aray[0]);
    sort(aray, size_of_aray);
}

void sort(int values[], int n){
    int temporary;

    int temporary_array[1000];
    int size_of_tmp_array = sizeof(temporary_array)/sizeof(temporary_array[0]);

    modify_all_aray_values_to_0(temporary_array, size_of_tmp_array);
    for(int i = 0; i < n; i++){
        temporary = values[i];
        temporary_array[temporary] = temporary_array[temporary]+1;
    }
    int tu;

    printf("Before getting modified: ");
    for(int i = 0; i < n; i++)
        printf("%i ", values[i]);

    printf("\n\n");


    printf("temporary_array: ");
    for(int i = 0; i < size_of_tmp_array; i++){
        if(temporary_array[i]>0) printf("%d-%i ", i,temporary_array[i]);
    }
    printf("\n\n");

    for(int i = 0; i < 100; i++)
        if(temporary_array[i] > 0)//If the count of a number is > 0
            for(tu = 0; 0 < temporary_array[i]; tu++ ){
                values[tu] = i;
                temporary_array[i] = temporary_array[i]-1;
                printf("%i,", values[tu]);
            }

    printf("\n\nShould be 1 2 2 2 3 3 4 4 5 6 7 9 20 44 56 57");
    printf("\n\nAfter Sorting: ");
    for(int i = 0; i < n; i++)
        printf("%i ", values[i]);

    printf("\n");
    return;
}

void modify_all_aray_values_to_0(int value[], int array_size){
    for(int i = 0; i < array_size; i++) value[i] = 0;
}