bzoj 1251: 序列终结者 平衡树,fhqtreap
链接
https://www.lydsy.com/JudgeOnline/problem.php?id=1251
思路
好简单的模板题
不过还是wrong了好几发
叶子节点要注意下,不能使用
遇到就不管
写的fhq-treap,OI中常数最大的平衡树,中间还T了一发
代码
#include <iostream>
#include <ctime>
#include <cstdlib>
#include <cstdio>
using namespace std;
const int N=5e5+7;
int read() {
int x=0,f=1;char s=getchar();
for(;s>'9'||s<'0';s=getchar()) if(s=='-') f=-1;
for(;s>='0'&&s<='9';s=getchar()) x=x*10+s-'0';
return x*f;
}
int n,m;
int ch[N][2],val[N],pri[N],siz[N],ma[N],tag_1[N],tag_2[N];
int max(int a,int b) {
return a>b?a:b;
}
void work1(int rt) {
if(!rt) return;
swap(ch[rt][0],ch[rt][1]);
tag_1[rt]^=1;
}
void work2(int rt,int k) {
if(!rt) return;
val[rt]+=k;
ma[rt]+=k;
tag_2[rt]+=k;
}
void pushdown(int rt) {
if(tag_1[rt]) {
work1(ch[rt][0]);
work1(ch[rt][1]);
tag_1[rt]=0;
}
if(tag_2[rt]) {
work2(ch[rt][0],tag_2[rt]);
work2(ch[rt][1],tag_2[rt]);
tag_2[rt]=0;
}
}
void pushup(int rt) {
ma[rt]=max(val[rt],max(ma[ch[rt][0]],ma[ch[rt][1]]));
siz[rt]=siz[ch[rt][0]]+siz[ch[rt][1]]+1;
}
int cnt;
int build(int l,int r) {
if(l>r) return 0;
int mid=(l+r)>>1,p=++cnt;
ma[p]=val[p]=0,pri[p]=rand(),siz[p]=1;
ch[p][0]=build(l,mid-1);
ch[p][1]=build(mid+1,r);
if(!ch[p][0]) ma[ch[p][0]]=-0x3f3f3f3f;
if(!ch[p][1]) ma[ch[p][1]]=-0x3f3f3f3f;
pushup(p);
return p;
}
int merge(int x,int y) {
pushdown(x),pushdown(y);
if(!x||!y) return x+y;
if(pri[x]<pri[y]) {
ch[x][1]=merge(ch[x][1],y);
pushup(x);
return x;
} else {
ch[y][0]=merge(x,ch[y][0]);
pushup(y);
return y;
}
}
void split(int now,int &x,int &y,int k) {
if(!now) x=y=0;
else {
pushdown(now);
if(siz[ch[now][0]]+1<=k)
x=now,split(ch[now][1],ch[x][1],y,k-siz[ch[now][0]]-1);
else
y=now,split(ch[now][0],x,ch[y][0],k);
pushup(now);
}
}
void debug(int now ){
pushdown(now);
if(!now) return;
debug(ch[now][0]);
cout<<val[now]<<" ";
debug(ch[now][1]);
}
int main() {
n=read(),m=read();
int rt=build(1,n);
for(int i=1;i<=m;++i) {
int opt=read(),l=read(),r=read(),x,y,z;
if(opt==1) {
int v=read();
split(rt,x,z,r);
split(x,x,y,l-1);
work2(y,v);
rt=merge(merge(x,y),z);
}
else if(opt==2) {
split(rt,x,z,r);
split(x,x,y,l-1);
work1(y);
rt=merge(merge(x,y),z);
} else {
split(rt,x,z,r);
split(x,x,y,l-1);
printf("%d\n",ma[y]);
rt=merge(merge(x,y),z);
}
// debug(rt);puts("");
}
return 0;
}
/*
10 3
1 3 9 -5705
2 2 6
3 7 8
*/