對拍練習

去年的對拍noip上用不了...

不知道是否是機子的問題...換了一種對拍。

以洛谷11月月賽T2爲例。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;

int n;

int h[320],vis[320];

LL ans;

void dfs(int now,int a,LL scor)
{
    if(a==n)
    {
        ans=max(ans,scor);
        return ;
    }
    for(int i=1;i<=n;i++)
    {
        if(vis[i]) continue;
        vis[i]=true;
        dfs(i,a+1,scor+(h[now]-h[i])*(h[now]-h[i]));
        vis[i]=false;
    }
}

int main()
{
    freopen("rand.txt","r",stdin);
    freopen("baoli.txt","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&h[i]);
    dfs(0,0,0);
    cout<<ans<<endl;
    return 0;
}

暴力程序

 

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;

int n;

int L,R;

int h[320];

LL ans;

int main()
{
    freopen("rand.txt","r",stdin);
    freopen("my.txt","w",stdout);
    scanf("%d",&n);L=0;R=n;
    for(int i=1;i<=n;i++) scanf("%d",&h[i]);
    sort(h,h+n+1);
    while(L<R)
    {
        ans=ans+(h[R]-h[L])*(h[R]-h[L]);
        L++;
        ans=ans+(h[R]-h[L])*(h[R]-h[L]);
        R--;
    }
    cout<<ans<<endl;
    return 0;    
} 

正解

 

#include<iostream>
#include<cstring>
#include<ctime>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
int main()
{
    freopen("rand.txt","w",stdout);
    srand(time(0));
    int n;n=rand()%5+1;
    cout<<n<<endl;
    for(int i=1;i<=n;i++)
    {
        int x;x=rand()%100+2;
        cout<<x<<" ";
    }
    return 0;
} 

生成的數據

 

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
int main()
{
    while(1)
    {
        system("rand.exe");
        system("baoli.exe");
        system("my.exe");
        if(system("fc baoli.txt my.txt "))
        while(1);
    }
    return 0;
}

對拍

 要寫cstdlib

 

這四個程序