#include <stdio.h>

void bubble_sort(int *p, int n)
{
    int t, i, j;

    for (i = 0; i < n - 1; i++) {
        for (j = n - 1; j > i; j--) {
            if (*(p + j - 1) > *(p + j)) {
                t = *(p + j);
                *(p + j) = *(p + j - 1);
                *(p + j - 1) = t;
            }
        }
    }
}

int main()
{
    int a[] = { 2, 1, 7, 3, 6, 4, 8, 5, 9 };
    int n = sizeof(a) / sizeof(a[0]);
    int i;

    printf("元 a = { "); for (i = 0; i < n; i++) { printf("%d ", a[i]); } printf("}\n");
    bubble_sort(a, n);
    printf("後 a = { "); for (i = 0; i < n; i++) { printf("%d ", a[i]); } printf("}\n");

    return 0;
}