Submission #1264585

#	Time	Username	Problem	Language	Result	Execution time	Memory
1264585		nqknht	허수아비 (JOI14_scarecrows)	C++20	100 / 100	1179 ms	41808 KiB

scarecrows

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
pair<int,int> a[200004];
ll kq=0;int nex[200004],pv[200004],bit[200008],b[200005];
vector<int> vec[200005],vec1[200005];
int n;const int N=200005;
void update(int u,int v){
    while (u<=N){
        bit[u]+=v;
        u+=(u&(-u));
    }
}
ll get(int u){
    ll ans=0;
    while (u>0){
        ans+=bit[u];
        u-=(u&(-u));
    }
    return ans;
}
void f(int l,int r){
    if (l==r) return ;
    int mid=(l+r)/2;
    f(l,mid);f(mid+1,r);
    set<int> sr;
    vector<int> v;
    for (int i=mid+1;i<=r;i++){
        v.push_back(a[i].se);
        if (sr.size()==0) pv[a[i].se]=1;
        else{
            if (a[i].se<(*sr.begin())) pv[a[i].se]=1;
            else{
                auto id=sr.lower_bound(a[i].se);
                id--;
                pv[a[i].se]=*id;
            }
        }
        sr.insert(a[i].se);
    }
    sort(v.begin(),v.end());
    // cout<<v.size()<<endl;
    set<int> st;
    for (int i=mid;i>=l;i--) {
        int d=0,c=v.size()-1,ans=-1;
        while (d<=c){
            int g=(d+c)/2;
            if (v[g]<a[i].se) ans=g,d=g+1;
            else c=g-1;
        }
        
        if (ans>=0) vec[ans].push_back(a[i].se-1);
        if (st.size()==0) nex[a[i].se]=N;
        else{
            if (a[i].se>*st.rbegin()) nex[a[i].se]=N;
            else{
                nex[a[i].se]=*st.lower_bound(a[i].se);
            }
        }
        d=0;c=v.size()-1;ans=-1;
        while (d<=c){
            int g=(d+c)/2;
            if (nex[a[i].se]<v[g]) ans=g,c=g-1;
            else d=g+1;
        }
        // cout<<l<<" "<<r<<" "<<nex[a[i].se]<<endl;
        if (ans>0) vec1[ans-1].push_back(a[i].se-1);
        if (ans==-1) vec1[v.size()-1].push_back(a[i].se-1);
        st.insert(a[i].se);
    }
    for (int i=0;i<v.size();i++){
        update(pv[v[i]],1);
        for (auto z:vec[i]) kq-=get(z);
        for (auto z:vec1[i]) kq+=get(z);
    }
    for (int i=0;i<v.size();i++){
        update(pv[v[i]],-1);
        vec[i].clear();vec1[i].clear();
    }
    // cout<<l<<" "<<r<<" "<<v[0]<<endl;
}
int main(){
    if (fopen("DECOR.inp","r")){
        freopen("DECOR.inp","r",stdin);
        freopen("DECOR.out","w",stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n;
    for (int i=1;i<=n;i++) cin>>a[i].fi>>a[i].se;
    sort(a+1,a+n+1);
    for (int i=1;i<=n;i++) b[i]=a[i].se;
    sort(b+1,b+n+1);
    int d=1;
    map<int,int> mp;
    for (int i=1;i<=n;i++) if (mp[b[i]]==0) d++,mp[b[i]]=d;
    for (int i=1;i<=n;i++) a[i].se=mp[a[i].se];
    f(1,n);
    cout<<kq;
}

Compilation message (stderr)

scarecrows.cpp: In function 'int main()':
scarecrows.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen("DECOR.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
scarecrows.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen("DECOR.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 85 / 85