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답안 #1019809

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1019809 2024-07-11T09:11:59 Z ttamx Islands (IOI08_islands) C++17
90 / 100
 485 ms 131072 KB 
#include<bits/stdc++.h>

using namespace std;

using ll = long long;

const int N=1e6+5;

int n;
pair<int,int> nxt[N];
int deg[N];
queue<int> q;
vector<pair<int,int>> adj[N];
ll dp[N];
ll dia,ans;

template<class T>
struct Vector{
    T dat[N];
    int sz=0;
    void clear(){
        sz=0;
    }
    void push_back(T val){
        dat[sz]=val;
        sz++;
    }
    T* begin(){
        return dat;
    }
    T* end(){
        return dat+sz;
    }
};
Vector<pair<int,ll>> comp;

template<class T>
struct Deque{
    T dat[N*2];
    int l=0,r=0;
    bool empty(){
        return l>r;
    }
    void clear(){
        l=0,r=-1;
    }
    void push_back(T val){
        dat[++r]=val;
    }
    void pop_front(){
        l++;
    }
    void pop_back(){
        r--;
    }
    T front(){
        return dat[l];
    }
    T back(){
        return dat[r];
    }
};
Deque<pair<ll,int>> dq;

void dfs(int u){
    ll mx=0,mx2=0;
    for(auto [v,w]:adj[u]){
        dfs(v);
        mx2=max(mx2,dp[v]+w);
        if(mx<mx2)swap(mx,mx2);
    }
    dp[u]=mx;
    dia=max(dia,mx+mx2);
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n;
    for(int i=1;i<=n;i++){
        auto &[v,w]=nxt[i];
        cin >> v >> w;
        deg[v]++;
    }
    for(int i=1;i<=n;i++)if(!deg[i])q.emplace(i);
    while(!q.empty()){
        int u=q.front();
        q.pop();
        auto [v,w]=nxt[u];
        adj[v].emplace_back(u,w);
        if(--deg[v]==0)q.emplace(v);
    }
    for(int i=1;i<=n;i++)if(deg[i]){
        comp.clear();
        ll len=0;
        for(int u=i;deg[u];){
            comp.push_back({u,len});
            deg[u]=0;
            auto [v,w]=nxt[u];
            len+=w;
            u=v;
        }
        dia=0;
        dq.clear();
        for(auto [u,w]:comp){
            dfs(u);
            ll val=dp[u]-w;
            while(!dq.empty()&&dq.back().first<val)dq.pop_back();
            dq.push_back({val,u});
        }
        for(auto [u,w]:comp){
            if(dq.front().second==u)dq.pop_front();
            dia=max(dia,w+len+dp[u]+dq.front().first);
            ll val=dp[u]-w-len;
            while(!dq.empty()&&dq.back().first<val)dq.pop_back();
            dq.push_back({val,u});
        }
        ans+=dia;
    }
    cout << ans;
}

Subtask #1
33.0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 11 ms 23896 KB Output is correct
2 Correct 10 ms 23900 KB Output is correct
3 Correct 11 ms 23964 KB Output is correct
4 Correct 11 ms 24152 KB Output is correct
5 Correct 10 ms 23740 KB Output is correct
6 Correct 12 ms 23900 KB Output is correct
7 Correct 10 ms 23772 KB Output is correct
8 Correct 11 ms 23900 KB Output is correct
9 Correct 11 ms 23940 KB Output is correct
10 Correct 10 ms 23900 KB Output is correct
11 Correct 10 ms 23984 KB Output is correct

Subtask #2
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 23892 KB Output is correct
2 Correct 12 ms 23900 KB Output is correct

Subtask #3
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23900 KB Output is correct
2 Correct 11 ms 24156 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 24664 KB Output is correct
2 Correct 19 ms 25944 KB Output is correct
3 Correct 16 ms 24924 KB Output is correct
4 Correct 13 ms 24360 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 26964 KB Output is correct
2 Correct 26 ms 29008 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 49 ms 34532 KB Output is correct
2 Correct 46 ms 35152 KB Output is correct
3 Correct 57 ms 42516 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 75 ms 43348 KB Output is correct
2 Correct 125 ms 50816 KB Output is correct
3 Correct 88 ms 51468 KB Output is correct
4 Correct 126 ms 71504 KB Output is correct

Subtask #8
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 168 ms 66700 KB Output is correct
2 Correct 274 ms 86752 KB Output is correct
3 Correct 148 ms 62800 KB Output is correct
4 Correct 189 ms 78792 KB Output is correct
5 Correct 183 ms 77352 KB Output is correct
6 Correct 485 ms 78296 KB Output is correct
7 Correct 183 ms 98896 KB Output is correct

Subtask #9
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 220 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -