Submission #1255734

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255734		namhh	Feast (NOI19_feast)	C++20	100 / 100	98 ms	12104 KiB

feast

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
const int N = 3e5+5;
int n,k,a[N];
pii dp[N][2];
pii check(int mid){
    dp[1][0] = {0,0};
    dp[1][1] = {a[1]-mid,1};
    for(int i = 2; i <= n; i++){
        dp[i][0] = max(dp[i-1][0],dp[i-1][1]);
        pii c1 = {dp[i-1][0].fi+a[i]-mid,dp[i-1][0].se+1};
        pii c2 = {dp[i-1][1].fi+a[i],dp[i-1][1].se};
        dp[i][1] = max(c1,c2);
    }
    return max(dp[n][0],dp[n][1]);
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> k;
    for(int i = 1; i <= n; i++) cin >> a[i];
    int l = 0;
    int r = 1e14;
    while(l <= r){
        int mid = (l+r)/2;
        if(check(mid).se > k) l = mid+1;
        else r = mid-1;
    }
    cout << check(l).fi+k*l;
}

• 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