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Submission #1019822

# Submission time Handle Problem Language Result Execution time Memory
1019822 2024-07-11T09:16:18 Z ttamx Islands (IOI08_islands) C++17
100 / 100
 200 ms 66232 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;
ll dp[N],dp2[N],dia[N];
ll ans;

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];
        dp2[v]=max(dp2[v],dp[u]+w);
        if(dp[v]<dp2[v])swap(dp[v],dp2[v]);
        dia[v]=max({dia[v],dia[u],dp[v]+dp2[v]});
        if(--deg[v]==0)q.emplace(v);
    }
    for(int i=1;i<=n;i++)if(deg[i]){
        vector<pair<int,ll>> comp;
        ll len=0;
        for(int u=i;deg[u];){
            comp.emplace_back(u,len);
            deg[u]=0;
            auto [v,w]=nxt[u];
            len+=w;
            u=v;
        }
        ll res=0;
        deque<pair<ll,int>> dq;
        for(auto [u,w]:comp){
            res=max(res,dia[u]);
            ll val=dp[u]-w;
            while(!dq.empty()&&dq.back().first<val)dq.pop_back();
            dq.emplace_back(val,u);
        }
        for(auto [u,w]:comp){
            if(dq.front().second==u)dq.pop_front();
            res=max(res,w+len+dp[u]+dq.front().first);
            ll val=dp[u]-w-len;
            while(!dq.empty()&&dq.back().first<val)dq.pop_back();
            dq.emplace_back(val,u);
        }
        ans+=res;
    }
    cout << ans;
}

Subtask #1
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 344 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 344 KB Output is correct
7 Correct 0 ms 472 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct

Subtask #2
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 1 ms 348 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 524 KB Output is correct
2 Correct 1 ms 604 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 1112 KB Output is correct
2 Correct 6 ms 2460 KB Output is correct
3 Correct 4 ms 1372 KB Output is correct
4 Correct 2 ms 860 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3544 KB Output is correct
2 Correct 15 ms 5316 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 10740 KB Output is correct
2 Correct 32 ms 10396 KB Output is correct
3 Correct 46 ms 17188 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 60 ms 17748 KB Output is correct
2 Correct 76 ms 27756 KB Output is correct
3 Correct 77 ms 22604 KB Output is correct
4 Correct 148 ms 42804 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 137 ms 24404 KB Output is correct
2 Correct 168 ms 47972 KB Output is correct
3 Correct 117 ms 36696 KB Output is correct
4 Correct 162 ms 55060 KB Output is correct
5 Correct 152 ms 55352 KB Output is correct
6 Correct 196 ms 47188 KB Output is correct
7 Correct 170 ms 66232 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 145 ms 47700 KB Output is correct
2 Correct 147 ms 47600 KB Output is correct
3 Correct 164 ms 56496 KB Output is correct
4 Correct 159 ms 23636 KB Output is correct
5 Correct 153 ms 55136 KB Output is correct
6 Correct 150 ms 48716 KB Output is correct
7 Correct 200 ms 47696 KB Output is correct