Submission #1098050

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098050		nngan267	Feast (NOI19_feast)	C++17	100 / 100	125 ms	14160 KiB

feast

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define ii pair<int, int>
#define fi first
#define se second
#define pll pair<ll, ll>
#define db long double
#define plll pair<ll, pll>

const int maxn = 4e5+5;
const ll mod = 1e9+7;
const int iinf = 1e9+7;
const ll inf = 1e18+7;
const double eps = 1e-9;
const db pi = acos(-1);

int n, k;
int a[maxn];

void inp(){
    cin >> n >> k;
    for(int i=1; i<=n; i++){
        cin >> a[i];
    }
}

pll d[maxn][2];

pll check(ll lmb){
    d[1][0] = {0, 0};
    d[1][1] = {a[1] - lmb, 1};
    for(int i=2; i<=n; i++){
        d[i][0] = max(d[i-1][0], d[i-1][1]);
        d[i][1] = max(make_pair(d[i-1][0].fi + a[i] - lmb, d[i-1][0].se + 1),
                      make_pair(d[i-1][1].fi + a[i], d[i-1][1].se));
    }
    return max({d[n][0], d[n][1]});
}

void solve(){
    ll l = 0, r = inf;
    ll res = 0;
    while(l <= r){
        ll mid = (l+r)/2;
        if(check(mid).se >= k){
            res = mid;
            l = mid + 1;
        }
        else r = mid - 1;
    }
    cout << check(res).fi + res * k << "\n";
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int test = 1;
//    cin >> test;
    while(test--){
        inp();
        solve();
    }
    cerr << "\nTime elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << "s.\n";
}

• 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