75 lines
1.3 KiB
C++
75 lines
1.3 KiB
C++
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#include<bits/stdc++.h>
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using namespace std;
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#define int long long
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struct Cow{
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int dir;
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int h;
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};
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const int MAX_N = 1e5+5;
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Cow cow[MAX_N];
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int ans=0;
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struct Tree{
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int t[MAX_N];
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int n;
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// template<typename T>
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// Tree(const &)=delete;
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Tree(int n):n(n){}
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int lowbit(int x){
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return x&(-x);
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}
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void update(int dir,int delta){
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while(dir<=n){
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t[dir]+=delta;
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dir+=lowbit(dir);
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}
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}
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int query1to(int dir){
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int sum=0;
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while(dir>0){
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sum+=t[dir];
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dir-=lowbit(dir);
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}
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return sum;
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}
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};
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int readint();
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signed main(){
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const int n =readint();
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for(int i=1;i<=n;i++){
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cow[i]={
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.dir=i,
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.h=readint(),
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};
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}
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sort(cow+1,cow+n+1,[](Cow a,Cow b)->bool{
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return a.h>b.h;
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});
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Tree cmax(n);
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for(int i=1;i<=n;i++){
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cmax.update(cow[i].dir, 1);
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int l=cmax.query1to(cow[i].dir-1);
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int r = i-l-1;
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if(max(l,r)>min(l,r)*2)ans++;
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}
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cout<<ans<<endl;
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}
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int readint(){
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int x=0,w=1;
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char ch=0;
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while(!isdigit(ch)){
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if(ch=='-')w=-1;
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ch=getchar();
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}
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while(isdigit(ch)){
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x=x*10+(ch-'0');
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ch=getchar();
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}
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return x*w;
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}
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