Submission #1074384

#	Time	Username	Problem	Language	Result	Execution time	Memory
1074384		Persia	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	122 ms	50516 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];
  long long bit[N];
  void update(int u, long long x) {
    for(int i = u; i <= n; i += i & -i) bit[i] += x;
  }
  void rangeupdate(int u, int v, long long x) {
    update(u, x);
    update(v + 1, -x);
  }
  long long query(int u) {
    long long s = 0;
    for(int i = u; i; i -= i & -i) s += bit[i];
    return s;
  }
  long long query(int u, int v) {
    if (u > v) return 0;
    return query(v) - query(u - 1);
  }
  void dfs(int u, int par) {
    for(auto v : G[u]) if (v != par) {
//      if (u == 12) cout << v << "\n";
      dfs(v, u);
      dp[u][0] += dp[v][1];
    }
    dp[u][1] = dp[u][0];
    for(auto i : g[u]) {
      int x = i[0];
      int y = i[1];
      int c = i[2];
//      if (x == u) swap(x, y);
      int xx = jump(x, u);
      int yy = jump(y, u);
//      cout << x << " " << y << " " << c << "\n";
      dp[u][1] = max(dp[u][1], dp[u][0] + query(in[x]) + query(in[y]) - 2 * query(in[u]) + c);
    }
    rangeupdate(in[u], out[u], (dp[u][0] - dp[u][1]));
  }
  long long sol() {
    rep(i, 1, m) g[lca(qq[i][0], qq[i][1])].push_back(qq[i]);
    dfs(1, -1);
    long long res = 0;
    rep(i, 1, n) res = max(res, dp[i][1]);
//    rep(i, 1, n) cout << dp[i][1] << " ";
    return res;
  }
}

void Gen() {
  n = 1000;
  rep(i, 1, n - 1) {
    int u = i;
    int v = rnd(i + 1, n);
    G[u].push_back(v);
    G[v].push_back(u);
    e[i] = {u, v};
  }
  m = 14;
  rep(i, 1, m) {
    int u = rnd(1, n);
    int v = rnd(1, n);
    int c = rnd(1, 1e4);
    if (u > v) swap(u, v);
    qq[i] = {u, v, c};
  }
}

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);

//  Gen();
//  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 << n << " ";
//  cout << "\n";
//  rep(i, 1, n - 1) cout << e[i].fi << " " << e[i].se << "\n";
//  cout << m << "\n";
//  rep(i, 1, m) {
//    rep(j, 0, 2) cout << qq[i][j] << " ";
//    cout << "\n";
//  }
//  cout << "\n";
//  pair<int, int> res = {sub1::sol(), sub6::sol()};
//  cout << "\n";
//  cout << res.fi << " " << res.se;
//  cout << jump(5, 12);
}

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)
      |                         ^
election_campaign.cpp: In function 'void sub6::dfs(int, int)':
election_campaign.cpp:149:11: warning: unused variable 'xx' [-Wunused-variable]
  149 |       int xx = jump(x, u);
      |           ^~
election_campaign.cpp:150:11: warning: unused variable 'yy' [-Wunused-variable]
  150 |       int yy = jump(y, u);
      |           ^~

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