Submission #1017348

#	Time	Username	Problem	Language	Result	Execution time	Memory
1017348		_shr104	Feast (NOI19_feast)	C++14	18 / 100	101 ms	13936 KiB

feast

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pf push_front
#define fi first
#define se second
const ll mod = 1e9+7, mxn = 3e5+7;
ll n, a[mxn], k;
pair<ll,ll> lmb(ll x)
{
    pair<ll,ll> dp[mxn][2];
    dp[1][0] = {0,0}; dp[1][1] = {a[1]-x,1};
    for (ll i = 2; 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));
    }
    return max(dp[n][0],dp[n][1]);
}
void aliens()
{
    ll l = 0, r = 1e18, ans = -1;
    while (r >= l)
    {
        ll m = (r+l)>>1;
        ll opt = lmb(m).se;
        if (opt >= k)
        {
            l = m+1;
            ans = m;
        }
        else r = m-1;
    }
    cout << max(lmb(ans).fi + ans*k,0LL);
}
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
    cin >> n >> k;
    for (ll i = 1; i <= n; i++) cin >> a[i];
    aliens();
}   

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