Submission #424895

#TimeUsernameProblemLanguageResultExecution timeMemory
424895Mamnoon_SiamTwo Antennas (JOI19_antennas)C++17
13 / 100
3080 ms16620 KiB
// https://codeforces.com/blog/entry/66022?#comment-500622 #include <bits/stdc++.h> using namespace std; using ll = long long; using ii = pair<int, int>; using vi = vector<int>; #define all(v) begin(v), end(v) #define sz(v) (int)(v).size() #define fi first #define se second const int inf = 1e9 + 9; struct Node { vector<int> c, d; Node(int _, int n) { c.assign(n, -inf); d.assign(n, -inf); } void update_ci(int pos, int val) { c[pos-1] = val; } void update_di(int L, int R, int val) { for(int i = L-1; i < R; ++i) { d[i] = max(d[i], c[i] + val); } } int get_max_di(int L, int R) { int ret = -inf; for(int i = L-1; i < R; ++i) { ret = max(ret, d[i]); } return ret; } }; /*struct Node { Node *l = 0, *r = 0; int mx_di = -inf, mx_ci = -inf; int lo, hi; int lz = -inf; Node(int _lo, int _hi) : lo(_lo), hi(_hi) { if(lo < hi) { int mid = (lo + hi) >> 1; l = new Node(lo, mid); r = new Node(mid+1, hi); } } void upd(int val) { lz = max(lz, val); mx_di = max(mx_di, mx_ci + lz); } void push() { if(lo < hi) { l -> upd(lz); r -> upd(lz); } lz = -inf; } void update_ci(int pos, int ci) { if(lo == hi) { mx_ci = ci; } else { push(); if(pos <= l -> hi) l -> update_ci(pos, ci); else r -> update_ci(pos, ci); mx_ci = max(l -> mx_ci, r -> mx_ci); } } void update_di(int L, int R, int val) { // do d[i] max= c[i] + val, val negative in this problem if(hi < L or lo > R) return; if(L <= lo and hi <= R) { upd(val); } else { push(); l -> update_di(L, R, val); r -> update_di(L, R, val); mx_di = max(l -> mx_di, r -> mx_di); } } int get_max_di(int L, int R) { // max{ d[i] | i \in [L, R] } if(hi < L or lo > R) return -inf; if(L <= lo and hi <= R) return mx_di; push(); return max(l->get_max_di(L,R), r->get_max_di(L,R)); } };*/ const int N = 2e5 + 5; int n, q; int H[N], A[N], B[N]; int ans[N]; int L[N], R[N]; void solve() { vector<vi> offline(n+2), queries_w_R_at(n+1); for(int i = 1; i <= q; ++i) { queries_w_R_at[R[i]].emplace_back(i); } for(int i = 1; i <= n; ++i) { offline[min(n+1, i + A[i])].emplace_back(i); offline[min(n+1, i + B[i] + 1)].emplace_back(-i); } Node *tr = new Node(1, n); for(int i = 1; i <= n; ++i) { for(int j : offline[i]) { if(j < 0) { // del tr -> update_ci(-j, -inf); } else { // ins tr -> update_ci(j, H[j]); } } if(i - A[i] >= 1) { tr -> update_di(max(1, i - B[i]), i - A[i], -H[i]); } for(int j : queries_w_R_at[i]) { ans[j] = max(ans[j], tr -> get_max_di(L[j], R[j])); } } } int main(int argc, char const *argv[]) { #ifdef LOCAL freopen("in", "r", stdin); #endif fill(ans, ans+N, -inf); scanf("%d", &n); for(int i = 1; i <= n; ++i) { scanf("%d %d %d", &H[i], &A[i], &B[i]); } scanf("%d", &q); for(int i = 1; i <= q; ++i) { scanf("%d %d", &L[i], &R[i]); } solve(); for(int i = 1, j = n; i < j; ++i, --j) { swap(H[i], H[j]); swap(A[i], A[j]); swap(B[i], B[j]); } for(int i = 1; i <= q; ++i) { L[i] = n - L[i] + 1; R[i] = n - R[i] + 1; swap(L[i], R[i]); } solve(); for(int i = 1; i <= q; ++i) { printf("%d\n", ans[i] < 0 ? -1 : ans[i]); } return 0; } /* * use std::array instead of std::vector, if u can * overflow? * array bounds */

Compilation message (stderr)

antennas.cpp: In function 'int main(int, const char**)':
antennas.cpp:132:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |   scanf("%d", &n);
      |   ~~~~~^~~~~~~~~~
antennas.cpp:134:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |     scanf("%d %d %d", &H[i], &A[i], &B[i]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:136:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |   scanf("%d", &q);
      |   ~~~~~^~~~~~~~~~
antennas.cpp:138:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |     scanf("%d %d", &L[i], &R[i]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
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