2017 Multi-University Training Contest - Team 5

2017 Multi-University Training Contest - Team 5

06 / hdu6090    思维

tags： 主要是要想到，一个连通块中，最小化内部距离和，一定是一个点连剩下所有点。

#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define rep(i,a,b) for (int i=a; i<=b; ++i)
#define per(i,b,a) for (int i=b; i>=a; --i)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define MP make_pair
#define PB push_back
#define fi  first
#define se  second
typedef long long ll;
const int N = 200005;

int main()
{
    ll  n, m;
    int T;  scanf("%d", &T);
    while(T--)
    {
        scanf("%lld%lld", &n, &m);
        ll  ans=0;
        if(m<=n-1) {
            ans = m*m*2 + (n-(m+1))*(m+1)*n*2 + (n-(m+1))*(n-(m+2))*n;
        }
        else {
            ans = (n-1)*(n-1)*2 - (m-(n-1))*2;
            ans = max(ans, n*(n-1));
        }
        printf("%lld\n", ans);
    }

    return 0;
}

 

08  / hdu6092    dp，类似反过来的背包

tags： dp[now] 表示当前子集和为 now 的方案数，从1~m遍历过去，如果 dp[now] != b[now]  则需要更新，更新操作是：从 m~now ，dp[j] += dp[i-now] ，即类似背包反过来更新。

#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define rep(i,a,b) for (int i=a; i<=b; ++i)
#define per(i,b,a) for (int i=b; i>=a; --i)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define MP make_pair
#define PB push_back
#define fi  first
#define se  second
typedef long long ll;
const int N = 200005;

int n, m, a[60], cnt;
ll  b[N], dp[N];
int main()
{
    int T;  scanf("%d", &T);
    while(T--)
    {
        mes(dp, 0);  dp[0] = 1;
        cnt = 0;
        scanf("%d%d", &n, &m);
        rep(now,0,m)
        {
            scanf("%lld", &b[now]);
            while(dp[now]!=b[now])
            {
                per(i,m,now) dp[i] += dp[i-now];
                a[++cnt] = now;
            }
        }
        rep(i,1,n)
            if(i!=n) printf("%d ", a[i]);
            else printf("%d\n", a[i]);
    }

    return 0;
}

 

11 / hdu6095   水

#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define rep(i,a,b) for (int i=a; i<=b; ++i)
#define per(i,b,a) for (int i=b; i>=a; --i)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define MP make_pair
#define PB push_back
#define fi  first
#define se  second
typedef long long ll;
const int N = 200005;

int n, k, a[N];
int main()
{
    int T;  scanf("%d", &T);
    while(T--)
    {
        scanf("%d%d", &n, &k);
        rep(i,1,n) scanf("%d", &a[i]);
        sort(a+1, a+1+n);
        int cnt = 1;
        per(i,n-1,1)
        {
            if(a[i+1]-a[i]>k) break;
            else ++cnt;
        }
        printf("%d\n", cnt);
    }

    return 0;
}