Submission #1073943

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073943		Persia	Election Campaign (JOI15_election_campaign)	C++14	10 / 100	103 ms	49808 KiB

election_campaign

#include <bits/stdc++.h>
#define rep(i, l, r) for(int i = l; i <= r; i++)
#define rep2(i, l, r) for(int i = l; i >= r; i--)
#define fi first
#define se second
#define bit(i, x) (x >> i & 1)

using namespace std;
const int N = 1e5 + 3;
const int mod = 1e9 + 7;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
long long rnd(long long l, long long r) {
  return uniform_int_distribution<long long>(l, r)(rng);
}

int n, m;
vector<int> G[N];
pair<int, int> e[N];
array<int, 3> qq[N];
int in[N], out[N], rn[N], cnt;
int h[2 * N], rmq[2 * N][19], ct;
int f[N][18], dep[N];

void predfs(int u, int par) {
  in[u] = ++cnt;
  rn[cnt] = u;
  rmq[++ct][0] = in[u];
  h[in[u]] = ct;
  rep(i, 1, 17) f[u][i] = f[f[u][i - 1]][i - 1];
  for(auto v : G[u]) if (v != par) {
    f[v][0] = u;
    dep[v] = dep[u] + 1;
    predfs(v, u);
    rmq[++ct][0] = in[u];
  }
  out[u] = cnt;
}
int lca(int x, int y) {
  x = h[in[x]], y = h[in[y]];
  if (x > y) swap(x, y);
  int kk = 31 - __builtin_clz(y - x + 1);
  return rn[min(rmq[x][kk], rmq[y - (1 << kk) + 1][kk])];
}
bool path(int x, int y, int u) {
  bool flag = 0;
  flag |= (lca(y, u) == u && lca(x, u) == x);
  swap(x, y);
  flag |= (lca(y, u) == u && lca(x, u) == x);
  return flag;
}
bool check(int x, int y, int u, int v) {
  int p = lca(x, y);
  int g = lca(u, v);
  bool flag = 0;
  flag |= (path(p, x, u) || path(p, x, v) || path(p, x, g));
  flag |= (path(p, y, u) || path(p, y, v) || path(p, y, g));
  swap(x, u);
  swap(y, v);
  swap(p, g);
  flag |= (path(p, x, u) || path(p, x, v) || path(p, x, g));
  flag |= (path(p, y, u) || path(p, y, v) || path(p, y, g));
  return flag;
}
int jump(int x, int y) {
  if (x == y || !x || !y) return 0;
  if (dep[x] < dep[y]) swap(x, y);
  int delta = dep[x] - dep[y] - 1;
  rep(i, 0, 17) if (bit(i, delta)) x = f[x][i];
  return x;
}

namespace sub1{
  long long sol() {
    long long res = 0;
    rep(mask, 0, (1 << m) - 1) {
      long long s = 0;
      bool flag = 1;
      rep(i, 1, m) if (bit(i - 1, mask)) {
        s += qq[i][2];
        rep(j, i + 1, m) if (bit(j - 1, mask)) {
          if (check(qq[i][0], qq[i][1], qq[j][0], qq[j][1])) flag = 0;
        }
      }
      if (flag) res = max(res, s);
    }
    return res;
  }
}

namespace sub23{
  long long dp[N];
  long long sol() {
    rep(i, 1, n - 1) {
      assert(e[i].fi == i && e[i].se == i + 1);
    }
    sort(qq + 1, qq + m + 1, [&](array<int, 3> x, array<int, 3> y) {
      return x[1] < y[1];
    });
    long long res = 0;
    for(int i = 1, j = 1, k = 1; i <= m; ) {
      while(k <= qq[i][1]) {
        dp[k] = max(dp[k], dp[k - 1]);
        k++;
      }
      while(j <= m && qq[i][1] == qq[j][1]) {
        dp[qq[j][1]] = max(dp[qq[j][1]], dp[qq[j][0] - 1] + qq[j][2]);
        j++;
      }
      res = max(res, dp[qq[i][1]]);
      i = j;
    }
    return res;
  }
}

namespace sub6{
  long long dp[N][2];
  vector<array<int, 3>> g[N];
  void dfs(int u, int par) {
    for(auto v : G[u]) if (v != par) {
      dfs(v, u);
      dp[u][0] += dp[v][1];
    }
    dp[u][1] = dp[u][0];
    for(auto i : g[u]) {
      int x = (i[0] == u ? 0 : i[0]);
      int y = (i[1] == u ? 0 : i[1]);
      int c = i[2];
      dp[u][1] = max(dp[u][1], dp[x][0] + dp[y][0] + dp[u][0] - dp[jump(x, u)][1] - dp[jump(y, u)][1] + c);
    }
  }
  long long sol() {
    rep(i, 1, m) g[lca(qq[i][0], qq[i][1])].push_back(qq[i]);
    dfs(1, -1);
    return dp[1][1];
  }
}

int main(int argc, char* argv[]) {
   ios_base::sync_with_stdio(0);
   cin.tie(0); cout.tie(0);

  // freopen("testing.txt", "r", stdin);
//  freopen("outputing.txt", "w", stdout);

  cin >> n;
  rep(i, 1, n - 1) {
    int u, v; cin >> u >> v;
    G[u].push_back(v);
    G[v].push_back(u);
    e[i] = {u, v};
  }
  cin >> m;
  rep(i, 1, m) {
    int u, v, c; cin >> u >> v >> c;
    if (u > v) swap(u, v);
    qq[i] = {u, v, c};
  }
  predfs(1, -1);
  rep(j, 1, 18) rep(i, 1, ct - (1 << (j - 1))) rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
//  cout << sub1::sol();
//  cout << sub23::sol();
  cout << sub6::sol();
//  cout << jump(3, 5);
}

Compilation message (stderr)

election_campaign.cpp: In function 'long long int sub1::sol()':
election_campaign.cpp:79:30: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   79 |       rep(i, 1, m) if (bit(i - 1, mask)) {
      |                            ~~^~~
election_campaign.cpp:6:25: note: in definition of macro 'bit'
    6 | #define bit(i, x) (x >> i & 1)
      |                         ^
election_campaign.cpp:81:36: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   81 |         rep(j, i + 1, m) if (bit(j - 1, mask)) {
      |                                  ~~^~~
election_campaign.cpp:6:25: note: in definition of macro 'bit'
    6 | #define bit(i, x) (x >> i & 1)
      |                         ^

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