Submission #840058

#	Time	Username	Problem	Language	Result	Execution time	Memory
840058		socpite	Closing Time (IOI23_closing)	C++17	8 / 100	138 ms	36640 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)
{
    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)
{
    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 p, int endp)
{
    if (x == endp)
        return (onp[x] = true);
    for (auto v : g[x])
    {
        if (v.first == p)
            continue;
        onp[x] |= dfs_path(v.first, x, endp);
    }
    return onp[x];
}

long long solve2(int n, long long k, int x, int y)
{
    dfs_path(x, 0, y);
    long long re = 0;
    vector<long long> vec;
    for (int i = 0; i < n; i++)
    {
        if (onp[i])
        {
            k -= min(depX[i], depY[i]);
            re++;
            vec.push_back(max(depX[i], depY[i]) - min(depX[i], depY[i]));
        }
        else
        {
            vec.push_back(min(depX[i], depY[i]));
            vec.push_back(max(depX[i], depY[i]) - min(depX[i], depY[i]));
        }
    }
    if (k < 0)
        return 0;
    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 + re;
    }
    return vec.size() + 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, 0);
    dfsY(Y, 0);
    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:89:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |     for (int i = 0; i < vec.size(); i++)
      |                     ~~^~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 0 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17