Submission #676480

#	Time	Username	Problem	Language	Result	Execution time	Memory
676480		penguin133	Feast (NOI19_feast)	C++17	100 / 100	152 ms	15100 KiB

feast

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#define getchar_unlocked _getchar_nolock

int n, k, A[300005];
pi dp[300005][2];
int ans;

int c(int x){
	dp[0][0] = {0, 0};
	dp[0][1] = {-1e18, 0};
	for(int i=1;i<=n;i++){
		dp[i][0] = max(dp[i-1][0], dp[i-1][1]);
		dp[i][1] = max({make_pair(dp[i-1][0].fi + A[i] - x, dp[i-1][0].se + 1), make_pair(dp[i-1][1].fi + A[i], dp[i-1][1].se)});
	}
	pi tmp = max(dp[n][0], dp[n][1]);
	if(tmp.se <= k)ans = max(ans, tmp.fi + tmp.se * x);
	cerr << x << " " << tmp.fi << " " << tmp.se << '\n';
	return tmp.se;
}


void solve(){
	cin >> n >> k;
	for(int i=1;i<=n;i++)cin >> A[i];
	int lo = 0, hi = 1e15;
	while(lo <= hi){
		int mid = (lo + hi) >> 1;
		if(c(mid) >= k)lo = mid + 1;
		else hi = mid - 1;
	}
	cout << ans;
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	while(tc--){
		solve();
	}
}

Compilation message (stderr)

feast.cpp:41:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   41 | main(){
      | ^~~~

• 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