HDU 3308 LCIS

Problem Description

Given n integers.
You have two operations:
U A B: replace the Ath number by B. (index counting from 0)
Q A B: output the length of the longest consecutive increasing subsequence (LCIS) in [a, b].

 

Input

T in the first line, indicating the case number.
Each case starts with two integers n , m(0<n,m<=10 ⁵).
The next line has n integers(0<=val<=10 ⁵).
The next m lines each has an operation:
U A B(0<=A,n , 0<=B=10 ⁵)
OR
Q A B(0<=A<=B< n).

 

Output

For each Q, output the answer.

 

Sample Input

   
   
   
   

    
    
    
    1
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
   
   
   
   

 

Sample Output

   
   
   
   

    
    
    
    1
1
4
2
3
1
2
5
   
   
   
   

 

线段树单点修改区间合并

#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long LL;
const int maxn = 400005;
int n, m, T, l, r;
char s[2];

struct node
{
	int l, lr, lf, r, rl, rf, m;
};

struct ST
{
	int y;
	node f[maxn], ans;
	void merge(node &x, node &lx, node &rx)
	{
		x.lf = lx.lf;	x.rf = rx.rf;
		if (lx.lr == lx.r&&lx.rf < rx.lf) x.lr = rx.lr; else x.lr = lx.lr;
		if (rx.rl == rx.l&&rx.lf > lx.rf) x.rl = lx.rl; else x.rl = rx.rl;
		x.m = max(lx.m, rx.m);
		if (lx.rf < rx.lf) x.m = max(x.m, rx.lr - lx.rl + 1);
	}
	void build(int x, int l, int r)
	{
		f[x].l = l;		f[x].r = r;
		if (l == r)
		{
			scanf("%d", &y);
			f[x].lr = f[x].r;
			f[x].rl = f[x].l;
			f[x].lf = f[x].rf = y;
			f[x].m = 1;
		}
		else
		{
			int mid = (l + r) >> 1;
			build(x + x, l, mid);
			build(x + x + 1, mid + 1, r);
			merge(f[x], f[x + x], f[x + x + 1]);
		}
	}
	void insert(int x, int l, int r, int u, int v)
	{
		if (l == r) f[x].lf = f[x].rf = v;
		else
		{
			int mid = (l + r) >> 1;
			if (u <= mid) insert(x + x, l, mid, u, v);
			else insert(x + x + 1, mid + 1, r, u, v);
			merge(f[x], f[x + x], f[x + x + 1]);
		}
	}
	void find(int x, int l, int r, int ll, int rr)
	{
		if (ll <= l&&r <= rr)
		{
			if (ans.l == 0) ans = f[x];
			else
			{
				node t = ans;
				merge(ans, t, f[x]);
			}
		}
		else
		{
			int mid = (l + r) >> 1;
			if (ll <= mid) find(x + x, l, mid, ll, rr);
			if (rr > mid) find(x + x + 1, mid + 1, r, ll, rr);
		}
	}
	int solve(int l, int r)
	{
		ans.l = 0;
		find(1, 1, n, l, r);
		return ans.m;
	}
}st;

int main()
{
	scanf("%d", &T);
	while (T--)
	{
		scanf("%d%d", &n, &m);
		st.build(1, 1, n);
		while (m--)
		{
			scanf("%s%d%d", s, &l, &r);
			if (s[0] == 'Q') printf("%d\n", st.solve(l + 1, r + 1));
			else st.insert(1, 1, n, l + 1, r);
		}
	} 
	return 0;
}