HDU 3911 线段树区间染色 区间查询

九野的博客，转载请注明出处：http://blog.csdn.net/acmmmm/article/details/12110463

题意：

n个点

下面表示每个点的值(0或1)

m个操作

oper [u,v]  oper==1表示把区间所有值异或一下， ==0 表示询问区间上 连续为1的最长长度

 

#include<iostream>
#include<stdio.h>
#include<string>
#include<string.h>
#include<algorithm>
#include<set>
#include <cstdio>  
#include <cstring>  
#include <iostream>  
#include <math.h>  
#include <queue>  
#define N 100100
#define ll int  
#define L(x) x<<1  
#define R(x) x<<1|1  
#define Mid(x,y) (x+y)>>1  
using namespace std;  
inline ll Min(ll a,ll b){return a>b?b:a;}
inline ll Max(ll a,ll b){return a>b?a:b;}
int a[N];//1是黑

struct node{  
	int l,r;  
	int Win, Bin;//区间内黑白的最长
	int Llen, Rlen;// Llen 是 这个区间内 从区间左端点向右连续相同颜色的长度
	int Lc, Rc;//左端颜色

	bool lazy;

	int len(){return r-l+1;}
}tree[N*8];  
void change(int id){

	tree[id].lazy = 0;
	tree[id].Lc ^= 1;
	tree[id].Rc ^= 1;
	int temp = tree[id].Win;	tree[id].Win = tree[id].Bin; tree[id].Bin = temp;
	tree[L(id)].lazy ^= 1;
	tree[R(id)].lazy ^= 1;
}
void updata_up(int id){
	tree[id].Lc = tree[L(id)].Lc , tree[id].Rc = tree[R(id)].Rc ;
	tree[id].Rlen = tree[R(id)].Rlen;
	tree[id].Llen = tree[L(id)].Llen;
	
	tree[id].Bin=Max(tree[L(id)].Bin, tree[R(id)].Bin);
	tree[id].Win=Max(tree[L(id)].Win, tree[R(id)].Win);

	if( tree[L(id)].Rc == tree[R(id)].Lc)
	{
		if(tree[L(id)].Rc)
			tree[id].Bin = Max(tree[id].Bin, tree[L(id)].Rlen + tree[R(id)].Llen);
		else 
			tree[id].Win = Max(tree[id].Win, tree[L(id)].Rlen + tree[R(id)].Llen);

		if(tree[L(id)].Llen == tree[L(id)].len())
			tree[id].Llen = tree[L(id)].len() + tree[R(id)].Llen;
		if(tree[R(id)].Rlen == tree[R(id)].len())
			tree[id].Rlen = tree[R(id)].len() + tree[L(id)].Rlen;
	}
	
	if(tree[id].Lc==1)tree[id].Bin=Max(tree[id].Bin, tree[id].Llen);
	else tree[id].Win=Max(tree[id].Win, tree[id].Llen);

	if(tree[id].Rc==1)tree[id].Bin=Max(tree[id].Bin, tree[id].Rlen);
	else tree[id].Win=Max(tree[id].Win, tree[id].Rlen);
}
void Lazy(int id){
	if(!tree[id].lazy)
	 return ;
	tree[id].lazy = 0;
	tree[id].Lc ^= 1;
	tree[id].Rc ^= 1;
	int temp = tree[id].Win;	tree[id].Win = tree[id].Bin; tree[id].Bin = temp;
	tree[L(id)].lazy ^= 1;
	tree[R(id)].lazy ^= 1;
}
void build(int l,int r,int id){
	tree[id].l = l, tree[id].r = r;
	tree[id].lazy=0;
	if(l == r){
		tree[id].Llen=tree[id].Rlen=1;

		tree[id].Lc = tree[id].Rc = a[l];
		tree[id].Bin = a[l];
		tree[id].Win = 1-a[l];

		return ;
	}
	int mid = Mid(l,r);
	build( l, mid, L(id));		
	build( mid+1, r, R(id));
	updata_up(id);
}

void updata(int l, int r, int id){
	
	if(l == tree[id].l && tree[id].r == r)
	{Lazy(id); change(id); return ;}

	int mid=Mid(tree[id].l, tree[id].r);

	if(r <= mid)     updata(l, r, L(id));
	else if(mid < l) updata(l, r, R(id));
	else {
		updata(l, mid, L(id));
		updata(mid+1, r, R(id));
	}
	Lazy(L(id)),	Lazy(R(id));
	updata_up(id);
}
int query(int l, int r, int id){
	Lazy(id);
	if(l == tree[id].l && tree[id].r == r)
		return tree[id].Bin; 

	int mid=Mid(tree[id].l, tree[id].r);
	int r1=0, r2=0, ans=0;
	if(r <= mid) r1 = query(l, r, L(id));
	else if(mid < l)  r2 = query(l, r, R(id));
	else {
		r1 = query(l, mid, L(id));
		r2 = query(mid+1, r, R(id));

		if(tree[L(id)].Rc == 1 && tree[R(id)].Lc == 1)
			ans = Min(mid-l+1, tree[L(id)].Rlen) + Min(r-mid, tree[R(id)].Llen) ;
		r1 = Max(ans, r1);
	}
	ans = Max(r1, r2);
	return ans;
}
int main(){
	int n, que, oper, b, c;
	while(~scanf("%d",&n)){
		for(int i=1;i<=n;i++)scanf("%d", &a[i]);
		build(1,n,1);

		scanf("%d", &que);
		while(que--)
		{
			scanf("%d %d %d", &oper, &b, &c);

			if(oper)
				updata(b,c,1);

			else
				printf("%d\n", query(b,c,1));//问黑色

		}
	}
	return 0;
}

/*


0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 1 1 0   15,16
0 0 0 0 0 1 1 1 1 1 0 0 0 0 1 1 1 0 1 0    6,18
0 0 0 0 0 1 1 1 0 0 1 1 1 1 0 1 1 0 1 0    9,15

20 
0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 1 1 0
99

0 1 16
1 15 16
0 1 17
1 6 18 
0 1 18
1 9 15
0 1 19

1 1 1
0 1 20
1 1 2
1 3 5
0 1 11
1 1 20
0 1 12 
0 1 13
0 1 15
1 2 20
0 1 20
1 4 19
1 5 7
1 6 13
1 2 20
0 1 1
0 2 10
0 3 8
0 4 9
0 10 11
0 1 20


ans:

6
4
5
4
4
7
2
2
2
8
1
2
2
2
1
2

*/