Submission #563246

#	Time	Username	Problem	Language	Result	Execution time	Memory
563246		ngpin04	Road Closures (APIO21_roads)	C++14	26 / 100	55 ms	9436 KiB

roads

#include <bits/stdc++.h>
#include "roads.h"
#define fi first
#define se second
#define mp make_pair
#define TASK ""
#define bit(x) (1LL << (x))
#define getbit(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end() 
using namespace std;
template <typename T1, typename T2> bool mini(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maxi(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}
const int N = 1e5 + 5; 
const int oo = 1e9;
const long long ooo = 1e18;
const int mod = 1e9 + 7; // 998244353;
const long double pi = acos(-1);

vector <int> adj[N];

long long f[N][2];
long long dp[205][205];

int fr[N];
int to[N];
int w[N];
int n;

vector <long long> sub1() {
    sort(w, w + (n - 1), greater <int>());
    long long tot = accumulate(w, w + (n - 1), 0LL);
    vector <long long> res;
    res.push_back(tot);
    for (int i = 0; i < n - 1; i++)
        tot -= w[i], res.push_back(tot);
    return res;
}

vector <long long> sub2() {
    vector <long long> res;
    res.push_back(accumulate(w, w + (n - 1), 0LL));
    for (int i = 0; i < n; i++)
    for (int j = 0; j < 2; j++)
        f[i][j] = ooo;

    f[0][0] = 0;
    for (int i = 1; i < n; i++) {
        f[i][0] = min(f[i - 1][0], f[i - 1][1]) + w[i - 1];
        f[i][1] = f[i - 1][0];
    }
    res.push_back(min(f[n - 1][0], f[n - 1][1]));

    for (int i = 2; i < n; i++)
        res.push_back(0);
    return res;
}   

void dfs(int u, int k, int p = -1) {
    for (int i : adj[u]) {
        int v = fr[i] ^ to[i] ^ u;
        if (v == p)
            continue;
        dfs(v, k, u);
    }
    
    int deg = 0;

    for (int j = 1; j <= k; j++)
        dp[u][j] = ooo;

    vector <long long> f(k + 1, ooo), g(k + 1, ooo);
    f[0] = 0;
    for (int i : adj[u]) {
        int v = fr[i] ^ to[i] ^ u;
        if (v == p) 
            continue;

        for (int cur = deg; cur >= 0; cur--) {
            if (cur + 1 <= k)
                mini(g[cur + 1], f[cur] + dp[v][k - 1]);
            mini(g[cur], f[cur] + dp[v][k] + w[i]);
        }

        deg++;
        mini(deg, k);

        for (int cur = 0; cur <= deg; cur++) {
            f[cur] = g[cur];
            g[cur] = ooo;
        }
    }

    for (int j = 0; j <= k; j++) {
        dp[u][j] = f[j];
        if (j > 0)
            mini(dp[u][j], dp[u][j - 1]);
    }
}

long long solve(int k) {

    dfs(1, k);
    return dp[1][k];
}

vector <long long> sub3() {
    vector <long long> res;
    for (int i = 0; i < n - 1; i++) {
        adj[fr[i]].push_back(i);
        adj[to[i]].push_back(i);
    }

    for (int k = 0; k < n; k++)
        res.push_back(solve(k));
    return res;
}

vector<long long> minimum_closure_costs(int N, vector<int> U,
                                             vector<int> V,
                                             vector<int> W) {
    n = N;
    bool cond3 = (n <= 200);
    bool cond2 = true;
    for (int i = 0; i < n - 1; i++) {
        fr[i] = U[i];
        to[i] = V[i];
        w[i] = W[i];
        cond2 &= fr[i] == i && to[i] == i + 1;
    }
    if (*max_element(ALL(U)) == 0)  
        return sub1();

    if (cond2)
        return sub2();

    if (cond3)
        return sub3();
    return vector<long long>(N, 0);
}

//#include "grader.cpp"

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