关于c:快速排序

实现计划一

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

void display(int arr[], int length)
{for (int i = 0; i < length; i++) {printf("%d%s", arr[i], i == length - 1 ? "" :", ");
    }

    printf("\n");
}

void quick_sort(int* arr, int low, int high)
{if (low >= high) {return;}

    int i = low;
    int j = high;

    int pivot = arr[low];

    while (i < j) {while(i < j && arr[j] >= pivot) {j--;}

        if (i < j) {arr[i++] = arr[j];
        }

        while(i < j && arr[i] < pivot) {i++;}

        if (i < j) {arr[j--] = arr[i];
        }
    }

    arr[i] = pivot;

    quick_sort(arr, low, i-1);
    quick_sort(arr, i + 1, high);
}

int main(int argc, char const *argv[])
{int arr[] = {23, 322, 1, 54, 86, 2, 90, 102, 66, 233, 6, 98};

    int length = sizeof(arr) / sizeof(int);

    display(arr, length);

    quick_sort(arr, 0, length - 1);

    display(arr, length);

    return 0;
}

实现计划二

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

void display(int arr[], int length)
{for (int i = 0; i < length; i++) {printf("%d%s", arr[i], i == length - 1 ? "" :", ");
    }

    printf("\n");
}

int partition(int* arr, int low, int high) 
{if (low >= high) {return -1;}

    int i = low;
    int j = high;
    int pivot = arr[low];

    while(i < j) {while(i < j && arr[j] >= pivot) {j--;}

        if (i < j) {arr[i++] = arr[j];
        }

        while (i < j && arr[i] < pivot) {i++;}

        if (i < j)
        {arr[j--] = arr[i];
        }
    }

    arr[i] = pivot;

    return i;
}

void quick_sort(int* arr, int low, int high)
{if (low >= high) {return;}

    int index = partition(arr, low, high);

    quick_sort(arr, low, index - 1);
    quick_sort(arr, index + 1, high);
}

int main(int argc, char const *argv[])
{int arr[] = {23, 322, 1, 54, 86, 2, 90, 102, 66, 233, 6, 98};

    int length = sizeof(arr) / sizeof(int);

    display(arr, length);

    quick_sort(arr, 0, length - 1);

    display(arr, length);

    return 0;
}