Submission #1168974

#	Time	Username	Problem	Language	Result	Execution time	Memory
1168974		tnknguyen_	Feast (NOI19_feast)	C++20	18 / 100	145 ms	12160 KiB

feast

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

#define endl '\n' 
#define ll long long 
#define len(s) (int)s.size() 
#define int long long 

#define pii pair<int, int>
#define fi first
#define se second
#define MASK(k) (1LL << (k))

int n, k;
const int MX = 3e5 + 5;
int a[MX];
pii dp[MX][2];

pii solve(int lmb){
    for(int i=1; i<=n; ++i) dp[i][0] = dp[i][1] = {0, 0};
    // {sum with current penalty, # of arrays}
    dp[1][0] = {0, 0}; //do not create new array
    dp[1][1] = {a[1] - lmb, 1}; // create 1 array with penalty

    for(int i=2; i<=n; ++i){
        // do not do anything
        // dp[i][0] = max(dp[i-1][0], dp[i-1][1]);
        dp[i][0] = (dp[i-1][0].fi >= dp[i-1][1].fi ? dp[i-1][0] : dp[i-1][1]);
        // create new array with penalty or assign to previous array
        pii p1 = {dp[i-1][0].fi + a[i] - lmb, dp[i-1][0].se + 1};
        pii p2 = {dp[i-1][1].fi + a[i], dp[i-1][1].se};
        // dp[i][1] = max(p1, p2);
        dp[i][1] = (p1.fi >= p2.fi ? p1 : p2);
    }    

    // return max(dp[n][0], dp[n][1]);
    return (dp[n][0].fi >= dp[n][1].fi ? dp[n][0] : dp[n][1]);
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    //freopen("main.inp","r",stdin);
    //freopen("main.out","w",stdout);

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

    pii ans = {-1, -1};
    int lamda = -1;

    for(int l=0, r=1e18; l<=r; ){
        int mid = (l + r) >> 1;
        pii cost = solve(mid);
        if(cost.second >= k){
            l = mid + 1;
            ans = cost;
            lamda = mid;
        }
        else r = mid - 1;
    }
    cout << max(0LL, ans.fi + lamda*k);

    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