///huynhocute123/// #include<bits/stdc++.h> using namespace std; #define pii pair<int,int> #define piii pair<int,pair<int,int>> #define pb push_back #define FOR(i, a, b) for(int i = (a) , _b = (b); i <= _b; ++i) #define REP(i, a, b) for(int i = (b) , _a = (a); i >= _a; --i) #define ALL(v) v.begin(),v.end() #define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin); #define out(name) if(fopen(name, "w")) freopen(name, "w", stdout); //random_device rd; //mt19937 rng(rd()); //#pragma GCC optimize ("O3") //#pragma GCC optimize ("unroll-loops") //#pragma GCC target("popcnt") //#define int long long const int MAX = 1e9+9; const long long MAXLL = 1e18+9; const double pi = 3.14159265358979323846; const double rad = 3.14159265358979323846 /180; bool minimize(int &u, int v){ if(v < u){ u = v; return 1; } return 0; } bool maximize(int &u, int v){ if(v > u){ u = v; return 1; } return 0; } bool maximizell(long long &u, long long v){ if(v > u){ u = v; return 1; } return 0; } bool minimizell(long long &u, long long v){ if(v < u){ u = v; return 1; } return 0; } const int mod = 1e9 + 7; inline int fastPow(int a, int n){ if(n == 0) return 1; int t = fastPow(a, n >> 1); t = 1ll * t * t % mod; if(n & 1) t = 1ll * t * a % mod; return t; } const int maxN =232 ; struct Alien_Trick{ vector<vector<pair<long long ,long long>>>dp; vector<long long> a; int n; pair<long long , long long> SOL(long long lamba){ dp[1][0] = {0 , 0}; dp[1][1] = {a[1] - lamba, 1}; FOR(i, 2, n){ dp[i][0] = max(dp[i - 1][1] , dp[i - 1][0]); dp[i][1] = max( make_pair(dp[i - 1][0].first + a[i] - lamba, dp[i - 1][0].second + 1 ), make_pair(dp[i - 1][1].first + a[i] , dp[i - 1][1].second ) ); } return max(dp[n][1] , dp[n][0]); } void init(){ int k; cin >> n >> k; a.assign(n + 2, 0); dp.assign(n + 2 , vector<pair<long long ,long long>>() ); FOR(i, 1, n)dp[i].assign(4, pair<long long, long long >()); FOR(i, 1 , n)cin >> a[i]; long long l = 0 , r= 1e18 ,ans = -1; while(l <= r){ long long mid = (l + r)/2; pair<long long , long long> hih = SOL(mid); if(hih.second >= k){ ans = mid; l = mid + 1; }else r = mid - 1; } pair<long long , long long> hih = SOL(ans); cout << hih.first + ans * k; } }; Alien_Trick X; inline void solve(){ X.init(); } signed main(){ ios_base::sync_with_stdio(false); cin.tie(0); #define NAME "task" if(fopen(NAME".inp", "r")){ freopen(NAME".inp", "r" ,stdin); // freopen(NAME".out", "w" ,stdout); } int tc = 1; // cin >> tc; while( tc-- )solve(); cerr << '\n' << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s\n" ; }

feast.cpp: In function 'int main()':
feast.cpp:105:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |         freopen(NAME".inp", "r" ,stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~