C:按降序对 vector 元素进行排序

Question

我正在尝试创建一个函数来重新排列数组，使其按降序排列。该数组由正整数组成，没有两个相等的元素。这就是我所拥有的:

int check (int *v, int n){
int i;
for (i=0; i<n; i++){
    if (v[i] != -1){
        return -1;
        break;
    }
    else return 1;
}
}

void sortVector (int *v, int n){
    int i, k, j=0, vp[n];

while (check(v,n) == -1){   
    for (i=0; i<n; i++){
        for (k=i+1; k<n; k++){
            if (v[k] > v[i]) break;
            else if (k == n-1){
                vp[j] = v[i];
                v[i] = -1;
                j++;
            }               
        }
    }
}

for (i=0; i<n; i++)
    v[i] = vp[i];
}

这不能正常工作。过去一周我一直在思考这个问题，所以一些建议会很好。谢谢。

Answer 1

我尝试从上面的代码开始遵循您在评论中陈述的想法，并做了一些更改，这是两个最终功能

#include <stdio.h>

int check (int *v, int n)
{
    int i;
    for (i=0; i<n; i++)
    {
        if (v[i] != -1)
        {
            return -1; // break is useless because return has the same effect 
        }
    }
    return 1; // you need to add a return here to handle all the cases
              // the case if the loop is not entered you need to return a value 
}

void sortVector (int *v, int n)
{
    int i, k, j=0, vp[n];
    int maxIndex=0;//you need to add this variable in order to keep track of the maximum value in each iteration

    while (check(v,n) == -1)
    {
        for (i=0; i<n; i++)
        {
            maxIndex=i; //you suppose that the maximum is the first element in each loop 
            for (k=i+1; k<n; k++)
            {
                if (v[k] > v[maxIndex])
                  maxIndex=k; // if there is another element greater you preserve its index in the variable 
            }
           //after finishing the loop above you have the greatest variable in the array  which has the index stored in maxIndex
                    vp[i] = v[maxIndex]; // put it in vp array
                    v[maxIndex]=v[i];//put it in treated elements zone
                    v[i]=-1;// make it -1
                    j++;
        }
    }

    for (i=0; i<n; i++)
        v[i] = vp[i];
}

这是测试

int main()
{
    int tab[]= {1,152,24,11,9};
    sortVector (tab, 5);
    int i=0;
    for(i=0; i<5; i++)
    {
        printf("%d ",tab[i]);
    }
    return 0;
}

给出所需的输出

152 24 11 9 1

注意:您可以通过在同一数组上进行交换而不是分配另一个数组来改进代码!