Submission #840078

#	Time	Username	Problem	Language	Result	Execution time	Memory
840078		socpite	Closing Time (IOI23_closing)	C++17	43 / 100	178 ms	47356 KiB

closing

#include "closing.h"

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
const long long INF = 1e18;

int onp[maxn];
long long depX[maxn], depY[maxn];

vector<pair<int, int>> g[maxn];

void dfsX(int x, int p = -1)
{
    for (auto v : g[x])
    {
        if (v.first == p)
            continue;
        depX[v.first] = depX[x] + v.second;
        dfsX(v.first, x);
    }
}

void dfsY(int x, int p = -1)
{
    for (auto v : g[x])
    {
        if (v.first == p)
            continue;
        depY[v.first] = depY[x] + v.second;
        dfsY(v.first, x);
    }
}

long long solve1(int n, long long k)
{
    vector<long long> vec;
    vec.insert(vec.end(), depX, depX + n);
    vec.insert(vec.end(), depY, depY + n);
    sort(vec.begin(), vec.end());
    long long crr = 0;
    for (int i = 0; i < vec.size(); i++)
    {
        crr += vec[i];
        if (crr > k)
            return i;
    }
    return vec.size();
}

vector<int> path;

bool dfs_path(int x, int endp, int p = -1)
{
    if (x == endp)
        return (onp[x] = true);
    for (auto v : g[x])
    {
        if (v.first == p)
            continue;
        onp[x] |= dfs_path(v.first, endp, x);
    }
    return onp[x];
}

vector<long long> vec1, vec2;
vector<long long> knapsack[maxn];
int mark[maxn];

bool chk(pair<int, int> a)
{
    return a.second < mark[a.first];
}

long long tval(pair<int, int> a)
{
    if (chk(a))
        return knapsack[a.first][a.second];
    else
        return knapsack[a.first][a.second] + knapsack[a.first][a.second + 1];
}

long long eval(pair<int, int> a)
{
    if (chk(a))
        return knapsack[a.first][a.second] * 2;
    else
        return knapsack[a.first][a.second] + knapsack[a.first][a.second + 1];
}

int nxt(pair<int, int> a)
{
    if (chk(a))
        return a.second + 1;
    else
        return a.second + 2;
}

void dfs_gen(int x, int p, long long cnst)
{
    long long val;
    if (p == -1)
        val = 0;
    else
        val = min(depX[x], depY[x]);
    if (val > cnst)
        vec2.push_back(val);
    else
        vec1.push_back(val);
    for (auto v : g[x])
    {
        if (v.first == p || onp[v.first])
            continue;
        dfs_gen(v.first, x, cnst);
    }
}

struct cmp
{
    bool operator()(const pair<int, int> a, const pair<int, int> b) const
    {
        return eval(a) > eval(b);
    }
};

long long solve2(int n, long long k, int x, int y)
{
    dfs_path(x, y);
    int len = 0;
    for (int i = 0; i < n; i++)
    {
        if (onp[i])
        {
            k -= min(depX[i], depY[i]);
            vec1.clear();
            vec2.clear();
            long long inc = abs(depX[i] - depY[i]);
            dfs_gen(i, -1, inc);
            sort(vec1.begin(), vec1.end());
            sort(vec2.begin(), vec2.end());
            knapsack[len] = vec1;
            for (auto v : vec1)
                knapsack[len].push_back(inc);
            mark[len] = knapsack[len].size();
            for (auto v : vec2)
            {
                knapsack[len].push_back(v);
                knapsack[len].push_back(inc);
            }
            len++;
            // cout << i << endl;
            // for(auto v: knapsack[len])cout << v << " ";
            // cout << endl;
        }
    }
    // cout << "left " << k << endl;
    if (k < 0)
        return 0;
    long long re = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, cmp> pq;
    for (int i = 0; i < len; i++)
        pq.push({i, 0});
    while (!pq.empty())
    {
        auto x = pq.top();
        // cout << "pq " << x.first << " " << x.second << endl;
        pq.pop();
        if (tval(x) <= k)
        {
            k -= tval(x);
            re += !chk(x) + 1;
            if (nxt(x) < knapsack[x.first].size())
                pq.push({x.first, nxt(x)});
        }
        else
        {
            if (knapsack[x.first][x.second] <= k)
            {
                re++;
                break;
            }
        }
    }

    return re;
}

void reset(int n)
{
    for (int i = 0; i < n; i++)
    {
        g[i].clear();
        onp[i] = 0;
    }
    path.clear();
}

int max_score(int N, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
    reset(N);
    for (int i = 0; i < N - 1; i++)
    {
        g[U[i]].push_back({V[i], W[i]});
        g[V[i]].push_back({U[i], W[i]});
    }
    depX[X] = 0;
    depY[Y] = 0;
    dfsX(X);
    dfsY(Y);
    long long ans = max(solve1(N, K), solve2(N, K, X, Y));

    return ans;
}

Compilation message (stderr)

closing.cpp: In function 'long long int solve1(int, long long int)':
closing.cpp:42:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for (int i = 0; i < vec.size(); i++)
      |                     ~~^~~~~~~~~~~~
closing.cpp: In function 'long long int solve2(int, long long int, int, int)':
closing.cpp:142:23: warning: unused variable 'v' [-Wunused-variable]
  142 |             for (auto v : vec1)
      |                       ^
closing.cpp:172:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  172 |             if (nxt(x) < knapsack[x.first].size())
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 0 / 9
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• Subtask 8: 0 / 10
• Subtask 9: 0 / 17