Submission #1079920

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079920		hqminhuwu	Feast (NOI19_feast)	C++14	100 / 100	93 ms	12428 KiB

feast

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <ll,ll> pll;
typedef pair <int,int> pii;
typedef pair <int,pii> piii;

#define forr(_a,_b,_c) for(int _a = (_b); _a <= int (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> int (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < int (_c); ++_a)
#define st first
#define nd second
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"

template<class X, class Y>
    bool minz(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } return false;
    }
template<class X, class Y>
    bool maxz(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } return false;
    }

const int N = 5e5 + 5;
const ll oo = (ll) 1e16;
const ll mod = 1e9 + 7; // 998244353;

ll dp[N], cnt[N], a[N], n, k;

void calc (ll x){
    ll mx = -x, mxcnt = 0;
    forr (i, 1, n){
        dp[i] = dp[i - 1];
        cnt[i] = cnt[i - 1];

        if (maxz(dp[i], mx + a[i])){
            cnt[i] = mxcnt + 1;
        }

        if (maxz(mx, dp[i] - a[i] - x)){
            mxcnt = cnt[i];
        }
    }
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    #ifdef hqm
        freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
    #endif

    cin >> n >> k;

    forr (i, 1, n){
        cin >> a[i];
        a[i] += a[i - 1];
    }
    
    ll l = 0, r = mod * n;

    while (l < r){
        ll mid = (l + r + 1) >> 1;
        calc(mid);

        if (cnt[n] < k)
            r = mid - 1;
        else l = mid;
    }

    calc(l);

    //cout << l << " " << dp[n] << " " << cnt[n] << endl;
    cout << dp[n] + l * k;

    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