Submission #871575

#	Time	Username	Problem	Language	Result	Execution time	Memory
871575		MON	Feast (NOI19_feast)	C++14	100 / 100	255 ms	14056 KiB

feast

#include<iostream>
#include<vector>
#warning we made it
using namespace std;
using ll = long long;
using pii = pair<int,long long>;
 
constexpr int NMAX = 3e5 + 1;
const ll oo = 1e16;
 
int a[NMAX];
 
inline pii best(pii a,pii b)
{
   if(a.second != b.second) return (a.second > b.second ? a : b);
   return (a.first < b.first ? a : b);
}
 
pii solve(int n,ll l)
{
    pii dp[2][n + 1]; dp[0][0] = {0,0},dp[1][0] = {0,-oo};
    for(int i = 0 ; i < n ; i++)
        {
            dp[0][i + 1] = best(dp[0][i],dp[1][i]);
            dp[1][i + 1] = best({dp[0][i].first + 1,dp[0][i].second + a[i + 1] - l},
                                {dp[1][i].first,dp[1][i].second + a[i + 1]});
        }
    return best(dp[0][n],dp[1][n]);
}
 
int main()
{
    int n,k; cin >> n >> k;
    for(int i = 1; i <= n ; i++) cin >> a[i];
 
    ll st = 0 , dr = 1LL << 62 , lambda(0);
    while(st <= dr)
        {
            ll mid = st + (dr - st) / 2; pii now = solve(n,mid);
            if(now.first <= k) dr = mid - 1,lambda = mid;
            else st = mid + 1;
        }
 
    pii ans = solve(n,lambda);
    ll out = ans.second + lambda * ans.first;
 
    cout << out;
    //solve(n,1);
 
}

Compilation message (stderr)

feast.cpp:3:2: warning: #warning we made it [-Wcpp]
    3 | #warning we made it
      |  ^~~~~~~

• 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