Submission #754653

#	Time	Username	Problem	Language	Result	Execution time	Memory
754653		fanwen	Training (IOI07_training)	C++17	100 / 100	11 ms	4180 KiB

training

#include <bits/stdc++.h>

using namespace std;
using namespace chrono;

#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(it, s) for (__typeof(s.begin()) it = (s).begin(); it != (s).end(); ++it)

template <typename U, typename V> bool maximize(U &A, const V &B) { return (A < B) ? (A = B, true) : false; }
template <typename U, typename V> bool minimize(U &A, const V &B) { return (A > B) ? (A = B, true) : false; }

const int MAXN = 1e3 + 5;

int N, M, time_out[MAXN], deg[MAXN], high[MAXN], dp[MAXN][MASK(10)];
vector <int> adj[MAXN];
pair <int, int> par[MAXN];

struct Edge {
    int u, v, w, LCA;
    Edge(int u = 0, int v = 0, int w = 0) : u(u), v(v), w(w) {}
    bool operator < (const Edge &oth) { return time_out[LCA] < time_out[oth.LCA]; }
};

void dfs(int u, int p) {
    static int run = 0;
    run++;
    for (auto v : adj[u]) if(v != p) {
        par[v] = make_pair(u, MASK(deg[u]++));
        high[v] = high[u] + 1;
        dfs(v, u);
    }
    time_out[u] = ++run;
}

int lca(int u, int v) {
    if(high[u] < high[v]) swap(u, v);
    while(high[u] > high[v]) u = par[u].first;
    while(u != v) u = par[u].first, v = par[v].first;
    return u;
}

void process(void) {
    cin >> N >> M;
    vector <Edge> edges(M);
    int total_weights = 0;
    for (auto &[u, v, w, _] : edges) {
        cin >> u >> v >> w;
        if(!w) {
            adj[u].push_back(v);
            adj[v].push_back(u);
        } else total_weights += w;
    }
    dfs(1, 0);
    for (auto &[u, v, _, LCA] : edges) {
        LCA = lca(u, v);
    }
    sort(ALL(edges));
    for (auto [u, v, w, LCA] : edges) {
        if(w && high[u] % 2 != high[v] % 2) continue;
        pair <int, int> A, B;
        int cur = w;
        for (A = make_pair(u, 0); A.first != LCA; A = par[A.first]) 
            cur += dp[A.first][(MASK(deg[A.first]) - 1) ^ A.second];
        for (B = make_pair(v, 0); B.first != LCA; B = par[B.first]) 
            cur += dp[B.first][(MASK(deg[B.first]) - 1) ^ B.second];
        REP(mask, MASK(deg[LCA])) if(!(mask & A.second) && !(mask & B.second)) {
            maximize(dp[LCA][mask | A.second | B.second], dp[LCA][mask] + cur);
        }
    }
    cout << total_weights - dp[1][MASK(deg[1]) - 1];
}

signed main() {

    #define TASK "TASK"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    auto start_time = steady_clock::now();
    int test = 1;
    // cin >> test;
    for (int i = 1; i <= test; ++i) {
        process();
        // cout << '\n';
    }

    auto end_time = steady_clock::now();

    cerr << "\nExecution time : " << duration_cast<milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

Compilation message (stderr)

training.cpp: In function 'int main()':
training.cpp:82:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
training.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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