제출 #545651

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
545651		balbit	Feast (NOI19_feast)	C++14	12 / 100	157 ms	14908 KiB

feast

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

#define ll long long
#define f first
#define s second
#define pii pair<ll, ll>

#define MX(a,b) a=max(a,b)
#define MN(a,b) a=min(a,b)
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(), (x).end()

#define REP(i,n) for (int i = 0; i<n; ++i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define pb push_back

#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do( T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do( T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBIT

const int maxn = 3e5+5;
const ll inf = 1ll<<61;
ll A[maxn];
pii dp[maxn][2];

int n;

pair<ll, ll> operator + (pair<ll, ll> a, pair<ll, ll> b) {
    return {a.f + b.f, a.s + b.s};
}

pair<ll, ll> get(int p) {
    // beware of initial states!!
    dp[0][0] = {0, 0}; // no value, nothing taken yet
    dp[0][1] = {-inf, -inf};
    REP1(i,n) {
        dp[i][0] = dp[i][1] = {-inf, -inf};
        MX(dp[i][0], dp[i-1][0]); // continue not taking anything
        MX(dp[i][0], dp[i-1][0] + make_pair(p, 1)); // take an empty segment (?)
        MX(dp[i][0], dp[i-1][1]); // stop taking stuff
        MX(dp[i][1], dp[i-1][0] + make_pair(p + A[i], 1));
        MX(dp[i][1], dp[i-1][1] + make_pair(p + A[i], 1));
        MX(dp[i][1], dp[i-1][1] + make_pair(A[i], 0));
    }
    return max(dp[n][0], dp[n][1]);
}

inline ll DIV(ll a, ll b) {
    return a/b - ((a%b) && ((a^b)<0));
}

signed main(){
    ios::sync_with_stdio(0), cin.tie(0);
    bug(1,2);

    int k; cin>>n>>k;
    REP1(i,n) {
        cin>>A[i];
    }

    ll l = -2e9-10, r = 2e9+10;

    while (l!=r) {
        ll md = DIV((l+r),2);
        pair<ll, ll> gt = get(md);
        if (gt.s >= k) {
            // taking too many zones, gotta make the range smaller
            r = md;
        }else{
            l = md+1;
        }
    }

    pair<ll, ll> gt = get(l);
    // only linear difference from it
    bug(l, gt.f, gt.s);
    ll re = gt.f + (gt.s) * (-l);
    cout<<re<<endl;


}

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