Submission #832960

#	Time	Username	Problem	Language	Result	Execution time	Memory
832960		CSQ31	Feast (NOI19_feast)	C++17	0 / 100	19 ms	3764 KiB

feast

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int MAXN = 2e5+5;
const ll INF = 1e18;
int n,k;
ll a[MAXN],dp[MAXN];
ll find(ll x){
	vector<int>seg(n+1,0);
	dp[0] = 0;
	ll mx = 0;
	int cur = 0;
	for(int i=1;i<=n;i++){
		dp[i] = a[i] + mx - x;
		seg[i] = cur+1;
		
		if(dp[i-1] > dp[i]){
			dp[i] = dp[i-1];
			seg[i] = seg[i-1];
		}
		if(dp[i] - a[i] == mx)cur = max(cur,seg[i]);
		else if(dp[i] - a[i] > mx){
			mx = dp[i] - a[i];
			cur = seg[i];
		}
		
	}
	//cout<<x<<" "<<seg[n]<<'\n';
	return seg[n];
}
int main()
{
	owo
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		a[i]+=a[i-1];
	}
	ll l = -1e15,r = 1e15;
	while(r-l>1){
		ll m = (l+r)/2;
		if(find(m) >= k)l = m;
		else r = m;
	}
	find(l);
	cout<<dp[n] + k*1LL*l;
}

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