# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
401598 | 2021-05-10T14:40:57 Z | maximath_1 | Peru (RMI20_peru) | C++17 | 0 ms | 0 KB |
#include <bits/stdc++.h> #include "peru.h" using namespace std; #define ll long long const ll mod = 1e9 + 7; const ll base = 23; const ll inf_ll = mod * 2ll * mod + 69ll; const int MX = 2500005; ll pwbase[MX]; int n, k, v[MX]; ll dp[MX]; struct dt{ int id; ll dp_id, dp_min; }; deque<dt> dq; int vv = 0; void pop_front(){ if(dq.size()) dq.pop_front(); if(dq.size()){ ll dp_i = dq.front().dp_id; dq.front().dp_id = inf_ll; dq.front().dp_min = inf_ll; for(int i = 1; i < dq.size(); i ++){ if(dq[i].dp_id <= dp_i) break; vv ++; dq[i].dp_min = min(dq[i - 1].dp_min, dq[i].dp_id); } } } void push_back(int id){ if(dq.empty()){ dq.push_back((dt){id, inf_ll, inf_ll}); return; } ll bf = dp[dq.back().id]; dq.push_back((dt){id, bf + v[id], min(bf + v[id], dq.back().dp_min)}); return; } int solve(){ for(int i = 0; i < n; i ++){ if(dq.size() && i - dq.front().id >= k) pop_front(); while(dq.size() && v[i] >= v[dq.back().id]) dq.pop_back(); push_back(i); dp[i] = (ll)v[dq.front().id]; if(i >= k) dp[i] += dp[i - k]; if(dq.size()) dp[i] = min(dp[i], dq.back().dp_min); } assert(vv == 0); pwbase[0] = 1ll; for(int i = 1; i < n; i ++) pwbase[i] = (pwbase[i - 1] * 1ll * base) % mod; ll ans = 0ll; for(int i = 0; i < n; i ++){ dp[i] %= mod; (ans += (pwbase[n - 1 - i] * 1ll * dp[i]) % mod) %= mod; } return ans; }