Submission #1282147

#	Time	Username	Problem	Language	Result	Execution time	Memory
1282147		baotoan655	Election Campaign (JOI15_election_campaign)	C++20	100 / 100	93 ms	26952 KiB

election_campaign

#include <bits/stdc++.h>
#define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
using namespace std;

const int N = 1e5 + 5, L = 17;
int n, m;
vector<int> g[N];
int dep[N], up[N][L], in[N], out[N], tim;
int bit[N];
void upd(int i, int val) {
    for(++i; i < N; i += i & -i) bit[i] += val;
}
void upd(int l, int r, int val) {
    if(l > r) return;
    upd(l, val);
    upd(r + 1, -val);
}
int get(int i) {
    int res = 0;
    for(++i; i > 0; i -= i & -i) res += bit[i];
    return res;
}

struct sus {
    int a, b, c;
} a[N];

void dfs(int u, int p) {
    in[u] = ++tim;
    for(int v : g[u]) if(v != p) {
        dep[v] = dep[u] + 1;
        up[v][0] = u;
        for(int i = 1; i < L; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
        dfs(v, u);
    }
    out[u] = tim;
}
int lca(int u, int v) {
    if(dep[u] < dep[v]) swap(u, v);
    int k = dep[u] - dep[v];
    for(int i = L - 1; i >= 0; --i) if(k >> i & 1) u = up[u][i];
    if(u == v) return u;
    for(int i = L - 1; i >= 0; --i) {
        if(up[u][i] != up[v][i]) {
            u = up[u][i];
            v = up[v][i];
        }
    }
    return up[u][0];
}
vector<int> ve[N];
int dp[N];
void cal(int u, int p) {
    int sum = 0;
    for(int v : g[u]) if(v != p) {
        cal(v, u);
        sum += dp[v];
    }
    dp[u] = sum;
    for(int id : ve[u]) {
        int x = a[id].a, y = a[id].b, z = a[id].c;
        dp[u] = max(dp[u], get(in[x]) + get(in[y]) + z + sum);
    }
    upd(in[u], out[u], sum - dp[u]);
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    file("A") else file("task");
    cin >> n;
    for(int i = 1, u, v; i < n; ++i) {
        cin >> u >> v;
        g[u].emplace_back(v);
        g[v].emplace_back(u);
    }
    dfs(1, 0);
    cin >> m;
    for(int i = 1; i <= m; ++i) {
        cin >> a[i].a >> a[i].b >> a[i].c;
        int p = lca(a[i].a, a[i].b);
        ve[p].emplace_back(i);
    }
    cal(1, 0);
    cout << dp[1] << '\n';
    return 0;
}

Compilation message (stderr)

election_campaign.cpp: In function 'int main()':
election_campaign.cpp:2:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:70:5: note: in expansion of macro 'file'
   70 |     file("A") else file("task");
      |     ^~~~
election_campaign.cpp:2:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:70:5: note: in expansion of macro 'file'
   70 |     file("A") else file("task");
      |     ^~~~
election_campaign.cpp:2:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:70:20: note: in expansion of macro 'file'
   70 |     file("A") else file("task");
      |                    ^~~~
election_campaign.cpp:2:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:70:20: note: in expansion of macro 'file'
   70 |     file("A") else file("task");
      |                    ^~~~

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