HDU 3308 线段树 最长连续上升子序列 单点更新 区间查询

题意：

T个测试数据

n个数 q个查询

n个数 ( 下标从0开始)

Q u v 查询 [u, v ] 区间最长连续上升子序列 

U u v 把u位置改成v

 

#include<iostream>

#include<stdio.h>

#include<string.h>

#include<algorithm>

using namespace std;

#define N 101010

#define L(x) (x<<1)

#define R(x) (x<<1|1)

inline int Max(int a,int b){return a>b?a:b;}

inline int Min(int a,int b){return a<b?a:b;}



struct node

{

	int l,r;

	int mid(){ return (l+r)>>1; }

	int len(){ return r-l+1; }

	int Llen, Rlen, maxlen;



}tree[4*N];

int a[N];

void updata_up(int id){

	tree[id].Llen = tree[L(id)].Llen;

	tree[id].Rlen = tree[R(id)].Rlen;

	tree[id].maxlen = Max( tree[L(id)].maxlen, tree[R(id)].maxlen);



	if( a[ tree[L(id)].r ] < a[ tree[R(id)].l ] )

	{

		if( tree[L(id)].Llen == tree[L(id)].len())

		{

			tree[id].Llen += tree[R(id)].Llen;

			tree[id].maxlen = Max( tree[id].maxlen, tree[id].Llen);

		}

		if( tree[R(id)].Rlen == tree[R(id)].len() )

		{

			tree[id].Rlen += tree[L(id)].Rlen;

			tree[id].maxlen = Max( tree[id].maxlen, tree[id].Rlen);

		}

		tree[id].maxlen = Max( tree[id].maxlen, tree[L(id)].Rlen + tree[R(id)].Llen );



	}

	

}

void build(int l, int r, int id){

	tree[id].l = l,  tree[id].r = r;



	if(l==r){ tree[id].Llen = tree[id].Rlen = tree[id].maxlen =1; return ; }



	int mid = (l+r)>>1;

	build(l,   mid, L(id));

	build(mid+1, r, R(id));

	updata_up(id);

}



void updata(int pos,int id){

	if(tree[id].l == tree[id].r)return ;



	int mid = tree[id].mid();

	if( pos <= mid ) updata(pos, L(id));

	else updata(pos, R(id));

	updata_up(id);

}



int query(int l, int r, int id){

	if( l == tree[id].l && tree[id].r == r)

		return tree[id].maxlen;



	int mid = tree[id].mid();

	if(r <= mid)return query(l, r, L(id));

	else if(mid < l) return query(l, r, R(id));



	int L = query(l, mid, L(id)), R = query(mid+1, r, R(id));



	if( a[mid] < a[mid+1] ){

		int LL = Min( mid - l + 1, tree[L(id)].Rlen);

		int RR = Min( r - mid,     tree[R(id)].Llen);

		return Max( Max(L,R), LL+RR);

	}

	else return Max(L, R);

}



int main(){

	int T,n,q,i; scanf("%d",&T);

	while(T--){

		scanf("%d %d", &n, &q);

		for(i=1;i<=n;i++)scanf("%d",&a[i]);



		build(1, n, 1);

		while(q--)

		{

			char c = '-';

			while(c!='Q' && c!='U') c = getchar();

			int u,v; scanf("%d %d", &u, &v);

			

			if(c == 'Q')

				printf("%d\n", query(u+1, v+1, 1));

			else if(c == 'U')

			{ a[u+1] = v; updata(u+1, 1); }



		}

	}

	return 0;

}

/*

99

10 10

7 7 3 3 5 9 9 8 1 8 

Q 6 6

U 3 4

Q 0 1

Q 0 5

Q 4 7

Q 3 5

Q 0 2

Q 4 6

U 6 10

Q 0 9



10 99

1 2 3 4 5 6 7 8 9 10

Q 4 7

U 0 8

Q 0 9

U 8 8



Q 0 9



*/