Submission #1258963

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258963		son2008	Election Campaign (JOI15_election_campaign)	C++20	20 / 100	381 ms	327680 KiB

election_campaign

#include <bits/stdc++.h>
using namespace std;
#define ii pair<int, int>
#define fi first
#define se second
// #define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int, ii>
#define iiii pair<ii, ii>
#define base 29
#define eps 1e-8
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
int dx[] = {0LL, 0LL, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0LL, 0LL, 1, -1, 1, -1};
const int maxn = 1e5 + 5;
const int mod = 1e9 + 7;
int n, m, x[maxn], y[maxn], a[maxn], b[maxn], c[maxn], h[maxn], par[maxn], vis[maxn];
vector<int> g[maxn], path[maxn], ds[maxn];
void dfs(int u, int cha)
{
    for (int v : g[u])
    {
        if (v == cha)
            continue;
        par[v] = u;
        h[v] = h[u] + 1;
        dfs(v, u);
    }
}
int dp[maxn];
void xly(int u, int i)
{
    for (int x : path[i])
        vis[x] = true;
    int cnt = 0;
    for (int x : path[i])
    {
        for (int y : g[x])
        {
            if (par[u] != y && !vis[y])
                cnt += dp[y];
        }
    }
    dp[u] = max(dp[u], cnt + c[i]);
    for (int x : path[i])
        vis[x] = false;
}
void DFS(int u)
{
    for (int v : g[u])
    {
        if (par[u] == v)
            continue;
        DFS(v);
        dp[u] += dp[v];
    }
    for (int pos : ds[u])
    {
        xly(u, pos);
    }
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#define task "task"
    if (fopen(task ".inp", "r"))
    {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    cin >> n;
    for (int i = 1; i < n; i++)
    {
        cin >> x[i] >> y[i];
        g[x[i]].push_back(y[i]);
        g[y[i]].push_back(x[i]);
    }
    dfs(1, -1);
    cin >> m;
    for (int i = 1; i <= m; i++)
    {
        cin >> a[i] >> b[i] >> c[i];
        while (a[i] != b[i])
        {
            if (h[a[i]] < h[b[i]])
                swap(a[i], b[i]);
            path[i].push_back(a[i]);
            a[i] = par[a[i]];
        }
        path[i].push_back(a[i]);
        ds[a[i]].push_back(i);
    }
    DFS(1);
    cout << dp[1];
    cerr << endl
         << "TIME : " << clock() * 0.001 << "s" << endl;
}

Compilation message (stderr)

election_campaign.cpp: In function 'int main()':
election_campaign.cpp:74:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 5
• Subtask 3: 0 / 5
• Subtask 4: 0 / 30
• Subtask 5: 10 / 10
• Subtask 6: 0 / 40