Submission #884372

#	Time	Username	Problem	Language	Result	Execution time	Memory
884372		Requiem	Feast (NOI19_feast)	C++17	41 / 100	37 ms	51920 KiB

feast

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define INF 1e18
#define fi first
#define se second
#define endl "\n"
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define pi 3.14159265359
#define TASKNAME "party_new"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
const int MAXN = 2e3 +  9;
int pre[200005],a[200005];
int n,k, suma = 0;
bool sub1 = true;
main()
{
    fast;
   if (fopen(TASKNAME".inp","r")){
        freopen(TASKNAME".inp","r",stdin);
        freopen(TASKNAME".out","w",stdout);
   }
   cin>>n>>k;
   for(int i=1;i<=n;i++){
       cin>>a[i];
       suma += a[i];
       pre[i] = pre[i-1] + a[i];
       if (a[i] < 0) sub1 = false;
   }
   if (sub1){
       cout<<suma<<endl;
       return 0;
   }
   if (n * k <= 1e7){
       vector<vector<int>> dp(k+1,vector<int>(n+1,-INF));
       vector<vector<int>> opt(k+1,vector<int>(n+1,-INF));
       int ans = 0;
       for(int i=0;i<=n;i++){
           dp[0][i] = 0;
           opt[0][i] = max( ((i>0) ? opt[0][i-1] : -1000000000000000000), dp[0][i] - pre[i]);
       }
       for(int i=1;i<=k;i++){
           for(int j=1;j<=n;j++){
               maximize(dp[i][j],dp[i][j-1]);
               maximize(dp[i][j], opt[i-1][j-1] + pre[j]);
               maximize(ans, dp[i][j]);
//               cout<<dp[i][j]<<' ';
           }
//           cout<<endl;
           for(int j=0;j<=n;j++){
              opt[i][j] = max( ((j>0) ? opt[i][j-1] : -1000000000000000000), dp[i][j] - pre[j]);
           }
       }
//       cout<<endl;
       cout<<ans<<endl;
   }
}

Compilation message (stderr)

feast.cpp:25:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main()
      | ^~~~
feast.cpp: In function 'int main()':
feast.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 0 / 29