UOJ #164. 【清华集训2015】V 线段树

#include<cmath>
#include<ctime>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<iomanip>
#include<vector>
#include<string>
#include<bitset>
#include<queue>
#include<set>
#include<map>
using namespace std;

typedef long long ll;

inline int read()
{
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch<='9'&&ch>='0'){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
return x*f;
}
void print(ll x)
{if(x<0)putchar('-'),x=-x;if(x>=10)print(x/10);putchar(x%10+'0');}

const int N=500100;
const ll inf=0X3f3f3f3f3f3f3f3fll;

int n;
struct seg_tree{ll a,b,c,d;}tr[N<<2];

inline void pushdown(int k)
{//cout<<k<<endl;
tr[k<<1].c=max(tr[k<<1].c,tr[k].c+tr[k<<1].a);
tr[k<<1].d=max(tr[k].d,max(tr[k<<1].d,tr[k<<1].b+tr[k].c));
tr[k<<1].a=max(-inf,tr[k].a+tr[k<<1].a);
tr[k<<1].b=max(tr[k<<1].b+tr[k].a,tr[k].b);

tr[k<<1|1].c=max(tr[k<<1|1].c,tr[k].c+tr[k<<1|1].a);
tr[k<<1|1].d=max(tr[k].d,max(tr[k<<1|1].d,tr[k<<1|1].b+tr[k].c));
tr[k<<1|1].a=max(-inf,tr[k].a+tr[k<<1|1].a);
tr[k<<1|1].b=max(tr[k<<1|1].b+tr[k].a,tr[k].b);
tr[k].a=tr[k].b=tr[k].c=tr[k].d=0;
}

void modify(int k,int l,int r,int x,int y,ll a,ll b)
{
if(l>=x&&r<=y)
{
tr[k].a=max(-inf,tr[k].a+a);
tr[k].b=max(tr[k].b+a,b);
tr[k].c=max(tr[k].a,tr[k].c);
tr[k].d=max(tr[k].b,tr[k].d);
return ;
}
int mid=(l+r)>>1;pushdown(k);
if(x<=mid)modify(k<<1,l,mid,x,y,a,b);
if(y>mid)modify(k<<1|1,mid+1,r,x,y,a,b);
}

inline ll query(int x)
{
register int l=1,r=n,mid,k=1;
while(l<r)
{
mid=(l+r)>>1;pushdown(k);
x<=mid?(k<<=1,r=mid):(k=k<<1|1,l=mid+1);
}
return max(tr[k].a,tr[k].b);
}

inline ll query_mx(int x)
{
register int l=1,r=n,mid,k=1;
while(l<r)
{
mid=(l+r)>>1;pushdown(k);
x<=mid?(k<<=1,r=mid):(k=k<<1|1,l=mid+1);
}
return max(tr[k].c,tr[k].d);
}

void build(int k,int l,int r)
{
if(l==r){tr[k].a=tr[k].c=read();return ;}
int mid=(l+r)>>1;
build(k<<1,l,mid);build(k<<1|1,mid+1,r);
}

int main()
{
n=read();int Q=read();
build(1,1,n);
register int opt,x,y,val;
while(Q--)
{
opt=read();x=read();
switch(opt)
{
case 1:y=read(),val=read();modify(1,1,n,x,y,val,0);break;
case 2:y=read(),val=read();modify(1,1,n,x,y,-val,0);break;
case 3:y=read(),val=read();modify(1,1,n,x,y,-inf,val);break;
case 4:print(query(x));puts("");break;
case 5:print(query_mx(x));puts("");break;
}
}
return 0;
}
/*
5 6
1 2 3 4 5
2 1 3 2
4 1
1 1 4 1
5 3
3 1 5 4
4 2

0
3
4
*/