Removed Interval HDU

问一个n元序列任删掉一段m长的子段后的LIS长度

n1e5,考虑枚举剩下的右端点参与答案贡献,我们需要右端点开始的LIS,以及删除段左边的,刚好比右端点小的点往前跑的LIS

前者可以去个负倒过来跑一下,后者双针边跑边更新就行

//#include<bits/stdc++.h>  
//#pragma comment(linker, "/STACK:1024000000,1024000000")   
#include<stdio.h>  
#include<algorithm>  
#include<queue>  
#include<string.h>  
#include<iostream>  
#include<math.h>  
#include<set>  
#include<map>  
#include<vector>  
#include<iomanip>  
using namespace std;  
  
const double pi=acos(-1.0);  
#define ll long long  
#define pb push_back

#define sqr(a) ((a)*(a))
#define dis(a,b) sqrt(sqr(a.x-b.x)+sqr(a.y-b.y))
#define FOR(a) for(int i=1;i<=a;i++)
const double eps=1e-10;
const int maxn=1e5+56;
const int inf=0x3f3f3f3f;

int a[maxn],b[maxn],dp[maxn],f[maxn];

int main(){
	int T;scanf("%d",&T);
	int kase=0;
	while(T--){
		int n,m;scanf("%d%d",&n,&m);
		for(int i=1;i<=n;i++){
			scanf("%d",&a[i]);
			b[i]=-a[i];
		}
		memset(dp,0x3f,sizeof dp);
		for(int i=n;i>=1;i--){
			int t=lower_bound(dp+1,dp+1+n,b[i])-dp;
			f[i]=t;		//i开头的最长长度
			dp[t]=b[i];
		}
		memset(dp,0x3f,sizeof dp);
		int ans=0;
		for(int i=m+1;i<=n;i++){	//枚举右端点
			int t=lower_bound(dp+1,dp+1+n,a[i])-dp;
			ans=max(ans,t-1+f[i]);
			*lower_bound(dp+1,dp+1+n,a[i-m])=a[i-m];
		}
		//在求左边lis过程中找右端点的lb
		int t=lower_bound(dp+1,dp+1+n,inf)-dp;//全左
		ans=max(ans,t-1);
		printf("Case #%d: %d
",++kase,ans);
	}
}



原文地址:https://www.cnblogs.com/Drenight/p/8611230.html