poj3667

链接:poj3667

题解

  • 线段树维护连续区间,hdu4553的削弱版,注意细节。。。因为一个小细节疯狂wa
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#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
#define rep(i,x,y) for(register int i=x;i<=y;++i)
#define repd(i,x,y) for(register int i=x;i>=y;--i)
#define ll long long
#define lson o<<1,l,mid
#define rson o<<1|1,mid+1,r
using namespace std;
const int N=1e6+7;
int llen[N<<2],rlen[N<<2],mlen[N<<2],cr[N<<2],n,m,x,y;
inline void pushup(int o,int len){
llen[o]=llen[o<<1];rlen[o]=rlen[o<<1|1];
if(llen[o]==len-(len>>1))llen[o]+=llen[o<<1|1];
if(rlen[o]==len>>1)rlen[o]+=rlen[o<<1];
mlen[o]=max(max(mlen[o<<1],mlen[o<<1|1]),rlen[o<<1]+llen[o<<1|1]);
}
inline void pushdown(int o,int len){
if(cr[o]==-1)return ;
cr[o<<1]=cr[o<<1|1]=cr[o];
llen[o<<1]=rlen[o<<1]=mlen[o<<1]=cr[o]?(len-(len>>1)):0;
llen[o<<1|1]=rlen[o<<1|1]=mlen[o<<1|1]=cr[o]?len>>1:0;
cr[o]=-1;
}
inline void build(int o,int l,int r){
llen[o]=rlen[o]=mlen[o]=r-l+1;cr[o]=-1;
if(l==r)return ;
int mid=l+r>>1;
build(lson);
build(rson);
}
inline void update(int o,int l,int r,int L,int R,int x){
if(L<=l&&R>=r){
cr[o]=x;
llen[o]=rlen[o]=mlen[o]=cr[o]?(r-l+1):0;
return ;
}
pushdown(o,r-l+1);
int mid=l+r>>1;
if(L<=mid)update(lson,L,R,x);
if(R>mid)update(rson,L,R,x);
pushup(o,r-l+1);
}
inline int query(int o,int l,int r,int L,int R,int x){
if(L==R)return L;
pushdown(o,r-l+1);
int Mid=L+R>>1,mid=l+r>>1;
if(mlen[o<<1]>=x)return query(lson,L,Mid,x);
if(rlen[o<<1]+llen[o<<1|1]>=x)return Mid-rlen[o<<1]+1;
return query(rson,Mid+1,R,x);
}
int main(){
//freopen("1.out","w",stdout);
while(~scanf("%d%d",&n,&m)){
build(1,1,n);
while(m--){
scanf("%d%d",&x,&y);
if(x==1){
int b;
if(mlen[1]<y)puts("0");
else {b=query(1,1,n,1,n,y);printf("%d\n",b);update(1,1,n,b,b+y-1,0);}
}
else {scanf("%d",&x);update(1,1,n,y,y+x-1,1);}
}
}
return 0;
}