Submission #938593

#	Time	Username	Problem	Language	Result	Execution time	Memory
938593		Lilypad	Feast (NOI19_feast)	C++14	63 / 100	123 ms	70996 KiB

feast

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll,ll>
#define pb push_back
#define fi first
#define se second

const ll N = 2003;

ll n,k,sum,b[300005],pref[300005];
ll mins,pos,idx;
vector<ll> a;
ll memo[N][N][2];

ll dp(ll x, ll y, ll stat) {
	if(x == idx+1) return 0;
	ll tmp = memo[x][y][stat];
	if(tmp != -1) return tmp;
	if(stat == 0) {
		tmp = dp(x+1,y,0);
		if(y > 0) {
			tmp = max(tmp,dp(x+1,y-1,1)+a[x]);
		}
	}
	else {
		tmp = max(dp(x+1,y,0),dp(x+1,y,1)+a[x]);
	}
	return memo[x][y][stat] = tmp;
}

int main() {
	memset(memo,-1,sizeof(memo));
	cin >> n >> k;
	for(int i=1; i<=n; i++) {
		cin >> b[i];
	}
	if(k == 1) {
		mins = 1e18;
		ll ans = 0;
		for(int i=1; i<=n; i++) {
			pref[i] = pref[i-1] + b[i];
			ans = max(ans,pref[i]-mins);
			mins = min(mins,pref[i]);
		}
		cout << ans << endl;
		return 0;
	}
	a.pb(0);
	for(int i=1; i<=n; i++) {
		if(b[i] >= 0) {
			sum += b[i];
			if(mins < 0) {
				a.pb(mins);
				mins = 0;
			}
		}
		else {
			mins += b[i];
			if(sum > 0) {
				a.pb(sum);
				sum = 0;
				pos++;
			}
		}
	}
	if(sum > 0) {
		a.pb(sum);
		pos++;
	}
	if(mins < 0) a.pb(mins);
	idx = a.size()-1;
	cout << dp(1,k,0) << endl;
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 0 / 29