Submission #1085271

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085271		quan606303	Feast (NOI19_feast)	C++14	100 / 100	119 ms	14512 KiB

feast

///0-0 : what is your motivation, quan606303?
///quan606303 : Hutao
/*idea : 
 
 
 
*/
#include <bits/stdc++.h>
#define int long long
#define ll long long
#define INTMAX INT_MAX
#define INTMIN INT_MIN
#define LONGMAX LLONG_MAX
#define LONGMIN LLONG_MIN
#define fi first
#define se second
#define memfull(a,b) memset(a,b,sizeof(a));
#define endl '\n'
#define file(a) freopen(a".inp","r",stdin); freopen(a".out","w",stdout);
using namespace std;
const int MOD=1e9+7;
const int maxn=3e5+7;;
int n,k,a[maxn],pre[maxn];
pair<int,int> dp[maxn][2];
pair<int,int> sub1(int pen)
{
    dp[0][0]={0,0};
    dp[0][1]={-pre[0]-pen,1};
    for (int i=1;i<=n;i++)
    { 
		dp[i][0]=max(dp[i-1][0],make_pair(dp[i-1][1].fi+pre[i],dp[i-1][1].se));
        dp[i][1]=max(dp[i-1][1],make_pair(dp[i][0].fi-pre[i]-pen,dp[i][0].se+1));
    }
    return dp[n][0];
}
int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
   // file("MUABANCO");
    cin>>n>>k;
    for (int i=1;i<=n;i++)cin>>a[i];
    for (int i=1;i<=n;i++)pre[i]=pre[i-1]+a[i];
    int l=0,r=1e18,ans=0;
    while (l<=r)
    {
        int mid=(l+r)/2;
        pair<int,int> cnt=sub1(mid);
        if (cnt.se<=k)
        {
            r=mid-1;
            ans=cnt.fi+cnt.se*mid;
        }
        else l=mid+1;
    }
    cout<<ans;
    return 0;
}

• 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