JuQueen
Time Limit: 5 Sec Memory Limit:
512 MB
Description
Input
Output
Sample Input
10 10 5
state 0
groupchange 2 9 7
state 9
groupchange 0 2 10
change 0 -5
Sample Output
0
7
7
3
-3 线段树lazy的巧用#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#define LL long long using namespace std; const int Num = 5000000; typedef struct Tree
{
int Min;//所表示区间的最大值 int Max;//所表示区间的最小值 int lazy;//区间所要变化的值
} Tree; Tree Tr[Num*5]; char str[15]; int c,n,o; void Pushup(int st)
{
Tr[st].Max = max(Tr[st<<1].Max,Tr[st<<1|1].Max); Tr[st].Min = min(Tr[st<<1].Min,Tr[st<<1|1].Min); Tr[st].Min += Tr[st].lazy; Tr[st].Max += Tr[st].lazy;
} void Build(int L,int R,int st)
{
Tr[st].Max=0; Tr[st].Min=0; Tr[st].lazy=0; if(L==R)
{
return ;
}
int mid =(L+R)>>1; Build(L,mid,st<<1); Build(mid+1,R,st<<1|1); Pushup(st);
} void Update(int L,int R,int st,int l,int r,int s)
{
if(L>r||R<l)
{
return ;
} if(L>=l&&R<=r)//区间更新
{
Tr[st].lazy+=s; Tr[st].Max+=s; Tr[st].Min+=s; return ;
}
int mid = (L+R)>>1; Update(L,mid,st<<1,l,r,s); Update(mid+1,R,st<<1|1,l,r,s); Pushup(st);
} Tree Query(int L,int R,int st,int l,int r,int s)
{
Tree p,q; p.Max=0; p.Min=c; if(L>r||R<l)
{
return p;
} if(L>=l&&R<=r)
{
p.Max=Tr[st].Max+s; p.Min=Tr[st].Min+s; return p;
}
int mid = (L+R)>>1; s+=Tr[st].lazy;
//将lazy所表示的逐层向下更新
if(l<=mid)
{
q=Query(L,mid,st<<1,l,r,s); p.Max=max(q.Max,p.Max); p.Min=min(q.Min,p.Min);
}
if(r>mid)
{
q=Query(mid+1,R,st<<1|1,l,r,s); p.Max=max(q.Max,p.Max); p.Min=min(q.Min,p.Min);
}
return p;
} int main()
{
int l,r,s; Tree p; while(~scanf("%d %d %d",&n,&c,&o))
{
Build(1,n,1); for(int i=0; i<o; i++)
{
scanf("%s",str); if(!strcmp(str,"change"))
{
scanf("%d %d",&l,&s); r=++l; p=Query(1,n,1,l,r,0); if(s<0)
{
if(p.Min+s>=0)
{
printf("%d\n",s); Update(1,n,1,l,r,s);
}
else
{
printf("%d\n",-p.Min); Update(1,n,1,l,r,-p.Min);
}
}
else
{
if(p.Max+s<=c)
{
printf("%d\n",s); Update(1,n,1,l,r,s);
}
else
{
printf("%d\n",c-p.Max); Update(1,n,1,l,r,c-p.Max);
}
} }
else if(!strcmp(str,"groupchange"))
{
scanf("%d %d %d",&l,&r,&s); l++,r++; p=Query(1,n,1,l,r,0); if(s<0)
{
if(p.Min+s>=0)
{
printf("%d\n",s); Update(1,n,1,l,r,s);
}
else
{
printf("%d\n",-p.Min); Update(1,n,1,l,r,-p.Min);
}
}
else
{
if(p.Max+s<=c)
{
printf("%d\n",s); Update(1,n,1,l,r,s);
}
else
{
printf("%d\n",c-p.Max); Update(1,n,1,l,r,c-p.Max);
}
}
}
else if(!strcmp(str,"state"))
{
scanf("%d",&l); r=++l; p=Query(1,n,1,l,r,0); printf("%d\n",p.Max);
}
}
}
return 0;
}