Submission #971442

#	Time	Username	Problem	Language	Result	Execution time	Memory
971442		mychecksedad	Feast (NOI19_feast)	C++17	100 / 100	135 ms	18036 KiB

feast

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;
const double eps = 0.00001;

int n, k;
ll a[N];
pair<ll, int> dp[N][2];
pair<ll, int> f(ll lambda){
  dp[1][0] = {0, 0};
  dp[1][1] = {a[1] - lambda, 1};
  for(int i = 2; i <= n; ++i){
    dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
    dp[i][1] = max(pair<ll,int>{dp[i - 1][0].first + a[i] - lambda, dp[i - 1][0].second + 1}, pair<ll,int>{dp[i - 1][1].first + a[i], dp[i - 1][1].second});
  }
  // cout << dp[1][1].first << ' ';
  return max(dp[n][0], dp[n][1]);
}
void solve(){
  cin >> n >> k;
  for(int i = 1; i <= n; ++i) cin >> a[i];
  ll l = 0, r = 1e18, lambda = 0;
  while(l <= r){
    ll m = (l+r)/2;
    if(f(m).second <= k){
      lambda = m;
      r = m - 1;
    }else{
      l = m + 1;
    }
  }

  // cout << f(lambda).second << ' ';

  cout << (ll)(f(lambda).first + lambda * k);
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:48:15: warning: unused variable 'aa' [-Wunused-variable]
   48 |   int tt = 1, aa;
      |               ^~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29