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Submission #555220

# Submission time Handle Problem Language Result Execution time Memory
555220 2022-04-30T09:45:47 Z alextodoran Islands (IOI08_islands) C++17
12 / 100
 374 ms 131072 KB 
/**
 ____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|

**/

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N_MAX = 1000000;

int N;
struct Edge {
    int to;
    int len;
};
vector <Edge> adj[N_MAX + 2];

bool seen[N_MAX + 2];
Edge par[N_MAX + 2];

tuple <int, int, int> backEdge;

void dfs (int u) {
    seen[u] = true;
    for (Edge e : adj[u]) {
        if (seen[e.to] == false) {
            par[e.to] = Edge{u, e.len};
            dfs(e.to);
        } else if (e.to != par[u].to) {
            backEdge = make_tuple(u, e.to, e.len);
        }
    }
}

bool root[N_MAX + 2];

ll maxAny[N_MAX + 2];
ll maxDown[N_MAX + 2];

void compute (int u) {
    vector <ll> maxDowns;
    for (Edge e : adj[u]) {
        if (seen[e.to] == false && root[e.to] == false) {
            compute(e.to);
            maxAny[u] = max(maxAny[u], maxAny[e.to]);
            maxDown[u] = max(maxDown[u], maxDown[e.to] + e.len);
            maxDowns.push_back(maxDown[e.to] + e.len);
        }
    }
    sort(maxDowns.begin(), maxDowns.end(), greater <ll> ());
    if ((int) maxDowns.size() >= 2) {
        maxAny[u] = max(maxAny[u], maxDowns[0] + maxDown[1]);
    }
    maxAny[u] = max(maxAny[u], maxDown[u]);
}

vector <vector <int>> rootGroups;

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> N;
    for (int u = 1; u <= N; u++) {
        Edge e;
        cin >> e.to >> e.len;
        adj[u].push_back(Edge{e.to, e.len});
        adj[e.to].push_back(Edge{u, e.len});
    }

    for (int u = 1; u <= N; u++) {
        if (seen[u] == false) {
            dfs(u);
            int v1, v2, len; tie(v1, v2, len) = backEdge;
            if (v1 == u) {
                swap(v1, v2);
            }
            par[v2] = Edge{v1, len};
            rootGroups.push_back({});
            int v = v1;
            while (v != v2) {
                root[v] = true;
                rootGroups.back().push_back(v);
                v = par[v].to;
            }
            root[v] = true;
            rootGroups.back().push_back(v);
        }
    }

    fill(seen + 1, seen + N + 1, false);
    for (int u = 1; u <= N; u++) {
        if (root[u] == true) {
            compute(u);
        }
    }

    ll answer = 0;
    for (vector <int> &roots : rootGroups) {
        ll totalLen = 0;
        ll maxLen = 0;
        for (int u : roots) {
            totalLen += par[u].len;
            maxLen = max(maxLen, maxAny[u]);
        }

        multiset <ll> s; ll len = 0;
        for (int i = (int) roots.size() - 1; i > 0; i--) {
            len += par[roots[i]].len;
            s.insert(maxDown[roots[i]] + len);
        }
        ll lazy = 0;

        for (int i = 0, u = roots[0]; i < (int) roots.size(); i++) {
            maxLen = max(maxLen, *s.rbegin() + lazy + maxDown[u]);
            s.insert(maxDown[u] - lazy);
            lazy += par[u].len;
            u = par[u].to;
            s.erase(s.find((maxDown[u] + totalLen) - lazy));
        }
        answer += maxLen;
    }
    cout << answer << "\n";

    return 0;
}

Subtask #1
12.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23764 KB Output is correct
2 Runtime error 162 ms 131072 KB Execution killed with signal 9
3 Correct 13 ms 23892 KB Output is correct
4 Runtime error 159 ms 131072 KB Execution killed with signal 9
5 Correct 11 ms 23764 KB Output is correct
6 Runtime error 161 ms 131072 KB Execution killed with signal 9
7 Runtime error 156 ms 131072 KB Execution killed with signal 9
8 Runtime error 152 ms 131072 KB Execution killed with signal 9
9 Runtime error 155 ms 131072 KB Execution killed with signal 9
10 Runtime error 158 ms 131072 KB Execution killed with signal 9
11 Correct 13 ms 23764 KB Output is correct

Subtask #2
0 / 3.0

# Verdict Execution time Memory Grader output
1 Runtime error 164 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #3
0 / 4.0

# Verdict Execution time Memory Grader output
1 Runtime error 165 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 161 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 182 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 213 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 163 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 374 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 356 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -