Submission #602234

#	Time	Username	Problem	Language	Result	Execution time	Memory
602234		Soumya1	Constellation 3 (JOI20_constellation3)	C++17	100 / 100	460 ms	79984 KiB

constellation3

#include <bits/stdc++.h>
#ifdef __LOCAL__
  #include <debug_local.h>
#endif
using namespace std;
const int mxN = 2e5 + 5;
const int lg = 20;
pair<int, int> h[mxN][lg];
int cur, up[mxN], lc[mxN], rc[mxN], low[mxN], out[mxN], par[mxN][lg];
vector<pair<int, int>> points[mxN];
long long dp[mxN][2];
long long bit[mxN];
int down[mxN], ll[mxN], rr[mxN];
pair<int, int> query(int l, int r) {
  int x = 31 - __builtin_clz(r - l + 1);
  return max(h[l][x], h[r - (1 << x) + 1][x]);
}
int build(int l, int r, int H, int p) {
  if (l > r) return -1;
  int x = ++cur;
  ll[x] = l, rr[x] = r, down[x] = H;
  auto [mx, idx] = query(l, r);
  par[x][0] = p;
  for (int j = 1; j < lg; j++) par[x][j] = par[par[x][j - 1]][j - 1];
  lc[x] = build(l, idx - 1, mx, x);
  rc[x] = build(idx + 1, r, mx, x);
  low[idx] = x;
  up[x] = mx + 1;
  out[x] = cur;
  return x;
}
void update(int i, long long v) { 
  for (; i < mxN; i += i & (-i)) bit[i] += v; 
}
long long query(int i) {
  long long r = 0;
  for (; i > 0; i -= i & (-i)) r += bit[i];
  return r;
}
void dfs(int u) {
  if (lc[u] != -1) {
    dfs(lc[u]);
    dp[u][0] += dp[lc[u]][1];
  }
  if (rc[u] != -1) {
    dfs(rc[u]);
    dp[u][0] += dp[rc[u]][1];
  }
  dp[u][1] = dp[u][0];
  for (auto [x, c] : points[u]) {
    dp[u][1] = max(dp[u][1], dp[u][0] + query(low[x]) + c);
  }
  update(u, dp[u][0] - dp[u][1]);
  update(out[u] + 1, dp[u][1] - dp[u][0]);
}
void testCase() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> h[i][0].first;
    h[i][0].second = i;
  }
  for (int j = 1; j < lg; j++) {
    for (int i = 1; i <= n - (1 << j) + 1; i++) {
      h[i][j] = max(h[i][j - 1], h[i + (1 << (j - 1))][j - 1]);
    }
  }
  par[1][0] = 1;
  build(1, n, n, 1);
  int m;
  cin >> m;
  long long sum = 0;
  while (m--) {
    int x, y, c;
    cin >> x >> y >> c;
    sum += c;
    int _x = x;
    x = low[x];
    for (int j = lg - 1; j >= 0; j--) {
      if (up[par[x][j]] <= y) x = par[x][j];
    }
    points[x].push_back({_x, c});
  }
  dfs(1);
  cout << sum - dp[1][1] << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  testCase();
}

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 65 / 65