注意！请在本地运行代码！（看着超级爽，也可以用来解压放松）

#include <bits/stdc++.h>
using namespace std ;
const int N=1000010 ;
int arr[N],n=1e6 ;
void read (int &x) //抄的
{
    x = 0; bool f = 0; char ch = getchar();
    while (!isdigit (ch)) f ^= !(ch ^ 45), ch = getchar();
    while (isdigit (ch)) x = (x << 1) + (x << 3) + (ch & 15), ch = getchar();
    x = f ? -x : x;
}
void random_data()
{
    freopen("data.in","w",stdout) ;
    for(int i=1;i<=n;i++)
        printf("%d ",rand()*rand()) ;
    fclose(stdout) ;
}
void test_unstable_sort()
{
    freopen("data.in","r",stdin) ;
    freopen("data.out","w",stdout) ;
    for(int i=1;i<=n;i++) read(arr[i]) ;
    int st=clock() ;
    sort(arr+1,arr+n+1) ;
    int ed=clock() ;
    cerr << "unstable sort use " << double(ed-st)/1000 << " seconds!\n" ;
    for(int i=1;i<=n;i++) printf("%d ",arr[i]) ;
    fclose(stdin) ;
    fclose(stdout) ;
}
void test_stable_sort()
{
    freopen("data.in","r",stdin) ;
    freopen("data.out","w",stdout) ;
    for(int i=1;i<=n;i++) read(arr[i]) ;
    int st=clock() ;
    stable_sort(arr+1,arr+n+1) ;
    int ed=clock() ;
    cerr << "stable sort use " << double(ed-st)/1000 << " seconds!\n" ;
    for(int i=1;i<=n;i++) printf("%d ",arr[i]) ;
    fclose(stdin) ;
    fclose(stdout) ;
}
int main()
{
    random_data() ;
    test_unstable_sort() ;
    test_stable_sort() ;
    return 0 ;
}

分别是稳定排序与不稳定排序！