Submission #1017285

#	Time	Username	Problem	Language	Result	Execution time	Memory
1017285		Thanhs	Feast (NOI19_feast)	C++14	100 / 100	120 ms	15188 KiB

feast

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define double long double
#define pb push_back
 
#define endl '\n'
#define fastIO ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define setmin(x,y) x=min((x),(y))
#define setmax(x,y) x=max((x),(y))
#define fi first
#define se second
 
mt19937 hdp(69420);
int rand(int l,int r){return l+((hdp()%(r-l+1))+r-l+1)%(r-l+1);}

const int N = 3e5 + 5;
const int mod = 1e9 + 7;
const int SQ = 450;
const int inf = 1e17;
const int L = 40;

int n,k,a[N];
pair<int,int> dp[N][2];

pair<int,int> solve(int lambda)
{
    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]-lambda,dp[i-1][0].se+1),make_pair(dp[i-1][1].fi+a[i],dp[i-1][1].se));
    }
    return max(dp[n][0],dp[n][1]);
}

signed main()
{
    fastIO
    // freopen("in.txt","r",stdin);
    // freopen("out.txt","w",stdout);
    dp[0][1]={-inf,0};
    cin>>n>>k;
    for(int i=1;i<=n;i++) cin>>a[i];
    int l=0,r=inf;
    while(l<r-1)
    {
        int m=l+r>>1;
        auto res=solve(m);
        if(res.se>k) l=m;
        else r=m;
    }
    auto res=solve(r);
    cout<<res.fi+res.se*r;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:49:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   49 |         int m=l+r>>1;
      |               ~^~

• 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