提出 #65939365

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ソースコード 拡げる

//People who believe in miracles are as amazing as miracles themselves.
#include<bits/stdc++.h>
#define ll long long
using namespace std;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-') f=-f;ch=getchar();}
    while(ch>='0'&&ch<='9')x=(x<<3)+(x<<1)+(ch^48),ch=getchar();
    return x*f;
}

const int N=3e5+10;
int n,a[N]; ll ans;

vector<int> vc,vc2;

inline void solve(){
    n=read();
    for(int i=1;i<=n;++i) a[i]=read();
    vc.emplace_back(1),vc2.emplace_back(1);
    for(int i=2;i<n;++i){
        if(a[i]<a[i-1]&&a[i]<a[i+1]) vc.emplace_back(i);
        if(a[i]>a[i-1]&&a[i]>a[i+1]) vc2.emplace_back(i);
    }
    vc.emplace_back(n),vc2.emplace_back(n);
    for(int i=2;i<n;++i)
        if(a[i]>a[i-1]&&a[i]>a[i+1]){
            int nxt=*lower_bound(vc.begin(),vc.end(),i);
            if(nxt<n){
                int pre=*--lower_bound(vc.begin(),vc.end(),i);
                int nxtt=*upper_bound(vc2.begin(),vc2.end(),nxt);
                ans+=(ll)(i-pre)*(nxtt-nxt);
            }
        }
    printf("%lld\n",ans);
}

signed main(){
#ifndef ONLINE_JUDGE
    freopen("../1.in","r",stdin);
    freopen("../1.out","w",stdout);
#endif
    return solve(),0;
}

提出情報

ジャッジ結果