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Submission #900438

# Submission time Handle Problem Language Result Execution time Memory
900438 2024-01-08T10:02:45 Z abcvuitunggio Islands (IOI08_islands) C++17
100 / 100
 220 ms 48072 KB 
#include <bits/stdc++.h>
using namespace std;
const int mxn=1000001;
const long long INF=1e18;
queue <int> q;
int n,p[mxn],l[mxn],last[mxn],r[mxn],x,u;
bitset <mxn> ch;
long long dp[mxn],d[mxn],val,res,a,b,sum,s;
int f(int i){
    return (r[i]==i?i:r[i]=f(r[i]));
}
int main(){
    ios_base::sync_with_stdio(NULL);cin.tie(nullptr);
    cin >> n;
    for (int i=1;i<=n;i++){
        cin >> p[i] >> l[i];
        last[p[i]]++;
        r[i]=i;
    }
    for (int i=1;i<=n;i++)
        if (!last[i])
            q.push(i);
    while (!q.empty()){
        u=q.front();
        q.pop();
        ch[u]=1;
        r[f(u)]=f(p[u]);
        d[p[u]]=max(max(d[p[u]],d[u]),dp[p[u]]+dp[u]+l[u]);
        dp[p[u]]=max(dp[p[u]],dp[u]+l[u]);
        if (!--last[p[u]])
            q.push(p[u]);
    }
    memset(last,0,sizeof(last));
    for (int i=1;i<=n;i++){
        if (ch[i])
            continue;
        sum=0,a=-INF,b=-INF;
        x=i;
        while (true){
            sum+=l[x];
            ch[x]=1;
            last[p[x]]=x;
            x=p[x];
            if (x==i)
                break;
        }
        val=0,s=sum;
        for (x=last[i];;x=last[x]){
            val=max(max(val,d[x]),dp[x]+max(a-s,b+sum+s));
            a=max(a,dp[x]+s);
            b=max(b,dp[x]-s);
            s-=l[last[x]];
            if (x==i)
                break;
        }
        res+=val;
    }
    cout << res;
}

Subtask #1
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 10584 KB Output is correct
2 Correct 1 ms 10584 KB Output is correct
3 Correct 1 ms 10588 KB Output is correct
4 Correct 1 ms 10588 KB Output is correct
5 Correct 1 ms 10588 KB Output is correct
6 Correct 1 ms 10588 KB Output is correct
7 Correct 2 ms 10584 KB Output is correct
8 Correct 2 ms 10584 KB Output is correct
9 Correct 1 ms 10588 KB Output is correct
10 Correct 2 ms 10716 KB Output is correct
11 Correct 1 ms 10588 KB Output is correct

Subtask #2
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 10588 KB Output is correct
2 Correct 2 ms 10844 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 10584 KB Output is correct
2 Correct 3 ms 10588 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 10844 KB Output is correct
2 Correct 8 ms 11356 KB Output is correct
3 Correct 5 ms 11084 KB Output is correct
4 Correct 3 ms 10844 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 11612 KB Output is correct
2 Correct 15 ms 11832 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 14164 KB Output is correct
2 Correct 28 ms 14172 KB Output is correct
3 Correct 38 ms 16988 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 22356 KB Output is correct
2 Correct 67 ms 25688 KB Output is correct
3 Correct 66 ms 18256 KB Output is correct
4 Correct 110 ms 27604 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 142 ms 21460 KB Output is correct
2 Correct 153 ms 27220 KB Output is correct
3 Correct 110 ms 29520 KB Output is correct
4 Correct 138 ms 33620 KB Output is correct
5 Correct 146 ms 33996 KB Output is correct
6 Correct 212 ms 32900 KB Output is correct
7 Correct 148 ms 33492 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 154 ms 46412 KB Output is correct
2 Correct 147 ms 47184 KB Output is correct
3 Correct 140 ms 32776 KB Output is correct
4 Correct 138 ms 32208 KB Output is correct
5 Correct 145 ms 46544 KB Output is correct
6 Correct 144 ms 45492 KB Output is correct
7 Correct 220 ms 48072 KB Output is correct