loj #6062. 「2017 山东一轮集训 Day2」Pair（线段树）

题目链接：https://loj.ac/problem/6062

留坑有空写

代码：

#include<bits/stdc++.h>using namespace std;const int MAXN=2e5+5;int a[MAXN],b[MAXN];int n,m,h;struct seg{#define lson l,mid,rt<<1#define rson mid+1,r,rt<<1|1int mi[MAXN<<2],lazy[MAXN<<2];inline void push_up(int rt){mi[rt]=min(mi[rt<<1],mi[rt<<1|1]);}inline void push_down(int rt){if(lazy[rt]){mi[rt<<1]+=lazy[rt];mi[rt<<1|1]+=lazy[rt];lazy[rt<<1]+=lazy[rt];lazy[rt<<1|1]+=lazy[rt];lazy[rt]=0;}}void build(int l,int r,int rt){lazy[rt]=0;if(l==r){mi[rt]=-(m-l+1);//printf("%d\n",mi[rt]);return;}int mid=(l+r)>>1;build(lson);build(rson);push_up(rt);}void update(int L,int R,int val,int l,int r,int rt){if(L>R)return ;if(L<=l&&r<=R){lazy[rt]+=val;mi[rt]+=val;return ;}push_down(rt);int mid=(l+r)>>1;if(L<=mid)update(L,R,val,lson);if(mid<R)update(L,R,val,rson);push_up(rt);}}se;int getid(int x){int p=upper_bound(b+1,b+1+m,x)-b-1;return p;}int pos[MAXN];void solve(){for(int i=1;i<=m;i++){scanf("%d",&b[i]);b[i]=h-b[i];}se.build(1,m,1);sort(b+1,b+1+m);for(int i=1;i<=n;i++){scanf("%d",&a[i]);a[i]=getid(a[i]);//printf("a[%d]->%d\n",i,a[i]);}int r=1;for(int i=1;i<=n;i++){while(r<=n&&se.mi[1]<0)se.update(1,a[r++],1,1,m,1);pos[i]=(se.mi[1]>=0)?r-1:-1;se.update(1,a[i],-1,1,m,1);}int ans=0;for(int i=1;i<=n;i++){if(pos[i]-i+1==m)ans++;}printf("%d\n",ans);}int main(){//freopen("in.txt","r",stdin);//freopen("out.txt","w",stdout);while(~scanf("%d%d%d",&n,&m,&h)){solve();}return 0;}