插入排序

算法思想：
默认前面的序列有序，将当前元素插入到合适的位置

#include <stdio.h>void insertion_sort(int [], int );void swap(int & ,int & );int main(void){    int i, n;    int a[10005];    scanf("%d", &n);    for (i = 1; i <= n; ++i)        scanf("%d", &a[i]);    insertion_sort(a, n);    for (i = 1; i <= n; ++i)        printf("%d\n", a[i]);    return 0;}void insertion_sort(int a[], int n){    int i, j;    for (i = 2; i <= n; ++i)        for (j = i - 1; j >= 1 && a[j] < a[j+1]; --j)            swap(a[j], a[j+1]);}void swap(int &a, int &b){    int t;    t = a;    a = b;    b = t;}