题目描述

输入n, 然后输入n个数
排序

样例

输入
5
3 1 2 4 5

输出
1 2 3 4 5

算法1

(归并排序) $O(n^2)$

时间复杂度

参考文献

C++ 代码

#include <cstdio>
const int N = 1e6+10;
int q[N], tmp[N];

void merge_sort(int q[], int l, int r) {
    if (l >= r) return ;

    int mid = l+r >> 1;
    merge_sort (q, l, mid);
    merge_sort (q, mid+1, r);

    int k = 0, i = l, j = mid+1;
    while (i<=mid && j<=r) {
        if (q[i] <= q[j]) tmp[k++]=q[i++];
        else tmp[k++]=q[j++];
    }

    while (i<=mid)  tmp[k++] = q[i++];
    while (j<=r)    tmp[k++] = q[j++];

    for (i = l , j = 0; i<=r; i++, j++) q[i] = tmp[j];
}

int main() {
    int n; 
    scanf("%d", &n);
    for (int i=0; i<n; i++) {
        scanf ("%d", &q[i]);
    }
    merge_sort(q, 0, n-1);
    for (int i=0; i<n; i++){
        printf("%d", q[i]);
        if (i<n-1) printf(" ");
    }
    return 0;
}