/*
        8. (**)编写整型值数组排序程序(冒泡排序、选择排序、快速排序--升序)
                 int a[] = {3,-9,32,77,63,-24,14,0,21,45};
        */
       // int a[] = {3,-9,32,77,63,-24,14,0,21,45};
        /*
        //冒泡排序：
        for (int i = 0; i < sizeof(a)/sizeof(int); i++) {
            for (int j = 0; j < sizeof(a)/sizeof(int) - i; j++) {
                if (a[j] > a[j+1]) {
                    int temp = a[j];
                    a[j] = a[j+1];
                    a[j+1] = temp;
                 }
            }
        }
        for (int i = 0; i < sizeof(a)/sizeof(int); i++) {
            printf("%d\t",a[i]);
        }
        */
        /*
        //选择排序
        for (int i = 0; i < sizeof(a)/sizeof(int); i++) {
            int minindex = i;
            for (int j = 0; j < sizeof(a)/sizeof(int)-i; j++) {
                if (a[minindex] < a[j]) {
                    minindex = j;
                }
                if (minindex != i) {
                    int temp = a[minindex];
                    a[minindex] = a[i];
                    a[i] = temp;
                }
            }
        }
        for (int i = 0 ; i < sizeof(a)/sizeof(int) ; i++) {
            printf("%d\t",a[i]);
        }
         */
        //快速排序  不会
        
请问一下 快速排序 的思想：