Submission #944731

#	Time	Username	Problem	Language	Result	Execution time	Memory
944731		guagua0407	Constellation 3 (JOI20_constellation3)	C++17	100 / 100	321 ms	77908 KiB

constellation3

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int mxn=2e5+5;
const int inf=1e9;
const ll inf2=1e18;
int a[mxn];
pair<int,int> table[mxn][18];
int up[mxn][18];
vector<pair<int,int>> st[mxn],en[mxn];
int l[mxn],r[mxn];
ll dp[mxn];
int ordl[mxn],ordr[mxn];
ll bit[mxn];
int cnt=0;

void update(int pos,ll val){
    for(;pos<mxn;pos+=(pos&-pos)){
        bit[pos]+=val;
    }
}

ll query(int pos){
    ll ans=0;
    for(;pos>0;pos-=(pos&-pos)){
        ans+=bit[pos];
    }
    return ans;
}

int get(int l,int r){
    int b=__lg(r-l+1);
    return max(table[l][b],table[r-(1<<b)+1][b]).s;
}

void go(int L,int R){
    if(L==R) return;
    int mid=get(L,R);
    if(mid>L){
        l[mid]=get(L,mid-1);
        up[l[mid]][0]=mid;
        go(L,mid-1);
    }
    if(mid<R){
        r[mid]=get(mid+1,R);
        up[r[mid]][0]=mid;
        go(mid+1,R);
    }
}

void dfs(int v){
    //cout<<v<<' '<<l[v]<<' '<<r[v]<<'\n';
    ordl[v]=++cnt;
    if(l[v]!=0){
        dfs(l[v]);
    }
    if(r[v]!=0){
        dfs(r[v]);
    }
    ordr[v]=cnt;
    if(l[v]!=0){
        update(ordl[v],dp[l[v]]);
        update(ordr[v]+1,-dp[l[v]]);
        update(ordl[l[v]],-dp[l[v]]);
        update(ordr[l[v]]+1,dp[l[v]]);
    }
    if(r[v]!=0){
        update(ordl[v],dp[r[v]]);
        update(ordr[v]+1,-dp[r[v]]);
        update(ordl[r[v]],-dp[r[v]]);
        update(ordr[r[v]]+1,dp[r[v]]);
    }
    dp[v]=dp[l[v]]+dp[r[v]];
    for(auto u:en[v]){
        int x=u.f;
        dp[v]=max(dp[v],query(ordl[x])+u.s);
    }
}

signed main() {_
    int n;
    cin>>n;
    a[0]=inf;
    //dp[0]=-inf2;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        table[i][0]={a[i],i};
    }
    for(int j=1;j<18;j++){
        for(int i=1;i+(1<<j)-1<=n;i++){
            table[i][j]=max(table[i][j-1],table[i+(1<<(j-1))][j-1]);
        }
    }
    int root=get(1,n);
    go(1,n);
    for(int j=1;j<18;j++){
        for(int i=1;i<=n;i++){
            up[i][j]=up[up[i][j-1]][j-1];
        }
    }
    int m;
    cin>>m;
    ll sum=0;
    for(int i=1;i<=m;i++){
        int x,y,c;
        cin>>x>>y>>c;
        sum+=c;
        int node=x;
        for(int j=17;j>=0;j--){
            int v=up[node][j];
            if(a[v]<y) node=v;
        }
        //cout<<st<<'\n';
        en[node].push_back({x,c});
        st[x].push_back({node,c});
    }
    dfs(root);
    cout<<sum-dp[root]<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

constellation3.cpp: In function 'void setIO(std::string)':
constellation3.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
constellation3.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 65 / 65