Submission #501548

#	Time	Username	Problem	Language	Result	Execution time	Memory
501548		Victor	Road Closures (APIO21_roads)	C++17	24 / 100	367 ms	7856 KiB

roads

// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")

#include "roads.h"

#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define per(i, a, b) for (int i = (b - 1); i >= (a); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
#define debug(x) cout << #x << " = " << x << endl

#define umap unordered_map
#define uset unordered_set

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;

const int INF = 1'000'000'007;

int n, k;
vii graph[2001];
ll memo[2001][2];

void dp(int u, int p) {
    ll sum = 0;
    vi diff;
    trav(edge, graph[u]) if (edge.first != p) {
        int v, w;
        tie(v, w) = edge;
        dp(v, u);
        sum += memo[v][0];
        diff.emplace_back((memo[v][1] + w) - memo[v][0]);
    }

    sort(all(diff));
    memo[u][0] = memo[u][1] = -1;
    int need_rem = (sz(graph[u])) - k;
    if(sz(diff))assert(diff.back() < INF);
    diff.emplace_back(INF);
    trav(val, diff) {
        if (need_rem <= 1 && val >= 0 && memo[u][1] == -1) memo[u][1] = sum;
        if (need_rem <= 0 && val >= 0 && memo[u][0] == -1) memo[u][0] = sum;
        sum += val;
        --need_rem;
    }

    //cout<<"u = "<<u<<' '<<memo[u][0]<<' '<<memo[u][1]<<endl;
}

vector<long long> minimum_closure_costs(int N, vector<int> U, vector<int> V, vector<int> W) {
    n = N;
    vll ans(n, 0);
    rep(i, 0, n - 1) {
        ans[0] += W[i];
        graph[U[i]].emplace_back(V[i], W[i]);
        graph[V[i]].emplace_back(U[i], W[i]);
    }

    rep(i, 1, n) {
        k = i;
        dp(0, 0);
        ans[i] = memo[0][0];
    }
    return ans;
}
/*
int main() {
    int N;
    assert(1 == scanf("%d", &N));

    vector<int> U(N - 1), V(N - 1), W(N - 1);
    for (int i = 0; i < N - 1; ++i) {
        assert(3 == scanf("%d %d %d", &U[i], &V[i], &W[i]));
    }

    vector<long long> closure_costs = minimum_closure_costs(N, U, V, W);
    for (int i = 0; i < static_cast<int>(closure_costs.size()); ++i) {
        if (i > 0) {
            printf(" ");
        }
        printf("%lld", closure_costs[i]);
    }
    printf("\n");
    return 0;
}*/

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22