Submission #1211258

#	Time	Username	Problem	Language	Result	Execution time	Memory
1211258		malta	Feast (NOI19_feast)	C++20	18 / 100	81 ms	10888 KiB

feast

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using i128 = __int128_t;

pair<i128,int> dpc(const vector<ll>& pfs, i128 C){
    int n = pfs.size()-1;
    vector<i128> dp(n+1, (i128)LLONG_MIN*2);
    vector<int> cnt(n+1, 0);
    dp[0]=0;
    cnt[0]=0;

    i128 val=0;
    int cnt0=0;

    for(int i = 1; i <= n; i++){
        dp[i]=dp[i-1];
        cnt[i]=cnt[i-1];
        i128 dpi = val+(i128)pfs[i]+C;
        int ci = cnt0+1;
        if(dpi>dp[i]){
            dp[i]=dpi;
            cnt[i]=ci;
        }
        i128 cur = dp[i]-(i128)pfs[i];
        if(cur>val){
            val=cur;
            cnt0=cnt[i];
        }
    }
    return { dp[n], cnt[n] };
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k;
    cin >> n >> k;
    vector<ll> a(n+1), pfs(n+1, 0);
    for(int i=1; i<=n; i++){
        cin>>a[i];
        pfs[i] = pfs[i-1]+a[i];
    }
    if (*max_element(a.begin()+1, a.end())<=0) {
        cout<<0<<"\n";
        return 0;
    }
    i128 lo=(i128)-1e14, hi=1e14;
    i128 c0=hi, dp0=0;

    while(lo<=hi){
        i128 mid = lo + ((hi-lo)>>1);
        auto [dpC, kC] = dpc(pfs, mid);
        if(kC>=k){
            c0=mid;
            dp0=dpC;
            hi = mid-1;
        }
        else lo = mid+1;

    }

    i128 ans128 = dp0 - c0 * k;
    ll ans = (ll)ans128;
    cout << ans << "\n";
    return 0;
}

• 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