HDU 3308 LCIS 线段树 单点更新+区间合并

感觉区间合并都一个样，没什么好说的。

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<sstream>
#include<cmath>
#include<climits>
#include<string>
#include<map>
#include<queue>
#include<vector>
#include<stack>
#include<set>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define pb(a) push_back(a)
#define INF 0x1f1f1f1f
#define lson idx<<1,l,mid
#define rson idx<<1|1,mid+1,r
#define PI  3.1415926535898
template<class T> T min(const T& a,const T& b,const T& c) {
    return min(min(a,b),min(a,c));
}
template<class T> T max(const T& a,const T& b,const T& c) {
    return max(max(a,b),max(a,c));
}
void debug() {
#ifdef ONLINE_JUDGE
#else

    freopen("d:\\in.txt","r",stdin);
    freopen("d:\\out1.txt","w",stdout);
#endif
}
int getch() {
    int ch;
    while((ch=getchar())!=EOF) {
        if(ch!=' '&&ch!='\n')return ch;
    }
    return EOF;
}
const int MAXN=100100;
struct node
{
    int maxx,pre,suf,lv,rv,len;
};
node tree[MAXN<<2];
void Merge(node &fa,node &l,node &r)
{
    fa.len=l.len+r.len;
    fa.maxx=max(l.maxx,r.maxx,r.lv>l.rv?l.suf+r.pre:-1);
    fa.lv=l.lv;fa.rv=r.rv;
    fa.pre=l.pre==l.len&&l.rv<r.lv?l.pre+r.pre:l.pre;
    fa.suf=r.suf==r.len&&l.rv<r.lv?r.suf+l.suf:r.suf;
}
int build(int idx,int l,int r)
{
    if(l==r)
    {
        int v;
        scanf("%d",&v);
        node &x=tree[idx];
        x.len=x.pre=x.suf=x.maxx=1;
        x.lv=x.rv=v;
        return 0;
    }
    int mid=(r+l)>>1;
    build(lson);
    build(rson);
    Merge(tree[idx],tree[idx<<1],tree[idx<<1|1]);
    return 0;
}
int update(int idx,int l,int r,int x,int v)
{
    if(l==r)
    {
        tree[idx].lv=tree[idx].rv=v;
        return 0;
    }
    int mid=(r+l)>>1;
    if(x<=mid)update(lson,x,v);
    else update(rson,x,v);
    Merge(tree[idx],tree[idx<<1],tree[idx<<1|1]);
    return 0;
}
node query(int idx,int l,int r,int tl,int tr)
{
    if(tl<=l&&tr>=r)
        return tree[idx];
    int mid=(r+l)>>1;
    if(tl<=mid&&tr>mid)
    {
        node q,a,b;
        a=query(lson,tl,tr);
        b=query(rson,tl,tr);
        Merge(q,a,b);
        return q;
    }else if(tl<=mid)
        return query(lson,tl,tr);
        else return  query(rson,tl,tr);
}
int main()
{
    int t;
    scanf("%d",&t);
    for(int ca=1;ca<=t;ca++)
    {
        int n,m;
        scanf("%d%d",&n,&m);
        build(1,0,n-1);
        for(int i=1;i<=m;i++)
        {
            char op=getch();
            if(op=='Q')
            {
                int a,b;
                scanf("%d%d",&a,&b);
                node q=query(1,0,n-1,a,b);
                printf("%d\n",q.maxx);
            }else
            {
                int x,v;
                scanf("%d%d",&x,&v);
                update(1,0,n-1,x,v);
            }
        }
    }
    return 0;
}