Submission #979270

#	Time	Username	Problem	Language	Result	Execution time	Memory
979270		michified	Training (IOI07_training)	C++17	100 / 100	32 ms	1028 KiB

training

#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
using namespace std;

struct edge_t {
    int from, to, cost, c1, c2, cont;
};

struct node_t {
    int par, depth;
    map<int, int> childs;
    vector<edge_t> es;
    vector<int> dp;
};

int n, m;
vector<node_t> tree;
vector<vector<int>> adj;
vector<edge_t> nontree;

void rootTree(int cur, int par) {
    node_t& u = tree[cur];
    if (par != -1) {
        u.par = par;
        u.depth = tree[par].depth + 1;
    }
    for (int v : adj[cur]) {
        if (v == par) continue;
        u.childs[v] = u.childs.size();
        rootTree(v, cur);
    }
}

pair<int, pair<int, int>> lca(int a, int b) {
    int c1 = -1, c2 = -1;
    while (tree[a].depth > tree[b].depth) {
        if (tree[a].par == b) c1 = a;
        a = tree[a].par;
    }
    while (a != b) {
        if (tree[a].par == tree[b].par) {
            c1 = a;
            c2 = b;
        }
        a = tree[a].par;
        b = tree[b].par;
    }
    return mp(a, mp(c1, c2));
}

void dfs(int cur) {
    node_t& u = tree[cur];
    u.dp.resize(1 << u.childs.size(), 0);
    for (auto& v : u.childs) dfs(v.first);
    int tmp, i, hi;
    for (edge_t& e : u.es) {
        tmp = e.from;
        if (tmp != cur) {
            e.cont += tree[tmp].dp.back();
            while (tree[tmp].par != cur) {
                e.cont += tree[tree[tmp].par].dp[(tree[tree[tmp].par].dp.size() - 1) - (1 << tree[tree[tmp].par].childs[tmp])];
                tmp = tree[tmp].par;
            }
        }
        if (e.c2 == -1) continue;
        tmp = e.to;
        if (tmp != cur) {
            e.cont += tree[tmp].dp.back();
            while (tree[tmp].par != cur) {
                e.cont += tree[tree[tmp].par].dp[(tree[tree[tmp].par].dp.size() - 1) - (1 << tree[tree[tmp].par].childs[tmp])];
                tmp = tree[tmp].par;
            }
        }
    }

    for (i = 0; i < u.dp.size(); i++) {
        for (auto& v : u.childs) {
            if (i & (1 << v.second)) u.dp[i] += tree[v.first].dp.back();
        }
        hi = 0;
        for (edge_t& e : u.es) {
            if ((i & (1 << u.childs[e.c1])) == 0 or (e.c2 != -1 and (i & (1 << u.childs[e.c2])) == 0)) continue;
            hi = max(hi, e.cont + u.dp[i - (1 << u.childs[e.c1]) - (e.c2 == -1 ? 0 : (1 << u.childs[e.c2]))]);
        }
        u.dp[i] = max(u.dp[i], hi);
    }
}

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

    cin >> n >> m;
    tree.resize(n + 1);
    adj.resize(n + 1);
    int tu, tv, tc, i, tot = 0;
    pair<int, pair<int, int>> res;
    for (i = 0; i < m; i++) {
        cin >> tu >> tv >> tc;
        if (tc == 0) {
            adj[tu].pb(tv);
            adj[tv].pb(tu);
        } else {
            nontree.pb({tu, tv, tc, -1, -1});
            tot += tc;
        }
    }
    rootTree(1, -1);

    for (edge_t& e : nontree) {
        if ((tree[e.from].depth + tree[e.to].depth) % 2 == 1) continue;
        if (tree[e.from].depth < tree[e.to].depth) swap(e.from, e.to);
        res = lca(e.from, e.to);
        tree[res.first].es.pb({e.from, e.to, e.cost, res.second.first, res.second.second, e.cost});
    }

    dfs(1);
    cout << tot - tree[1].dp.back();
    return 0;
}

Compilation message (stderr)

training.cpp: In function 'void dfs(int)':
training.cpp:77:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |     for (i = 0; i < u.dp.size(); i++) {
      |                 ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 7 / 7
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9