Submission #1285497

#	Time	Username	Problem	Language	Result	Execution time	Memory
1285497		diep38	Feast (NOI19_feast)	C++20	100 / 100	103 ms	12168 KiB

feast

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

#define ed "\n"
#define fi first
#define se second
#define db double
#define irs insert
#define pb push_back
#define mpa make_pair
#define pi pair<int,int>
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x>>i)&1)
#define ON(x, i) ((x)  MASK(i))
#define OFF(x, i) ((x) & ~MASK(i))
#define ALL(v) v.begin() , v.end()
#define bp(x) __builtin_popcount(x)
#define pii pair<int,pair<int,int>>
#define fl(i,a,b) for(int i=a;i>=b;--i)
#define fis(i,a,b) for(int i=a;i<=b;++i)
#define Radian(x) (x * acos(-1.0) / 180)
const double eps = 1e-9;
const int mod=1e9+7;
const int Mdem=998244353;
const int LOG=19;
const int base=31;
const int maxn=3e5+5;
const int bl = 320;
#define fast ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define gay(a) freopen(a".inp","r",stdin),freopen(a".out","w",stdout)
template <class T>
bool minimize(T &a, const T &b) {
    if(a > b) {a = b; return 1;}
    return 0;
}

template <class T>
bool maximize(T &a, const T &b) {
    if(a < b) {a = b; return 1;}
    return 0;
}
template <class T>
void compress(vector <T> &v) {
    sort(ALL(v));
    v.erase(unique(ALL(v)), (v).end());
}

void add(int &a, int b) {   a += b; if (a >= mod)   a -= mod;   }
void sub(int &a, int b) {   a -= b; if (a <  0)     a += mod;   }
int n, k;
int a[maxn];
pi dp[maxn][2];
pi check(int lamda){
    dp[1][0] = {0, 0};
    dp[1][1] = {a[1] - lamda, 1};
    fis(i, 2, n){
        dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
        dp[i][1] = max(mpa(dp[i - 1][0].fi + a[i] - lamda, dp[i - 1][0].se + 1),
                       mpa(dp[i - 1][1].fi + a[i], dp[i - 1][1].se));
    }
    return max(dp[n][0], dp[n][1]);
}

signed main(){
    fast;
    cin >> n >> k;
    fis(i, 1, n){
        cin >> a[i];
    }
    int l = 1, r = *max_element(a + 1, a + n + 1) * n, ans = 0;
    while(l <= r){
        int mid = l + r >> 1;
        if(check(mid).second >= k){ ans = mid; l =  mid + 1;}
        else r = mid - 1;
    }
    pi t = check(ans);
    cout << t.fi + k * ans << ed;
    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