Submission #1175316

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175316		sasde	Feast (NOI19_feast)	C++20	41 / 100	1051 ms	251048 KiB

feast

#include<bits/stdc++.h>
#define int long long
#define task "strdel"
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
using namespace std;
const int N=1e6+5,lg=20,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
 return u+rd()%(v-u+1);
}
int n,a[N],k,dp[3000][3000],s[N];
struct seg
{
int st[3000*4];
void build(int id,int r,int l){
  if(r==l){
    st[id]=a[r];
    return;
  }
  int mid=(r+l)>>1;
  build(id<<1,r,mid);
  build(id<<1|1,mid+1,l);
  st[id]=max(st[id<<1],st[id<<1|1]);
}
void update(int id,int r,int l,int i,int val){
  if(r==l){
    st[id]=val;
    return;
  }
  int mid=(r+l)>>1;
  if(mid>=i)update(id<<1,r,mid,i,val);
  else update(id<<1|1,mid+1,l,i,val);
  st[id]=max(st[id<<1],st[id<<1|1]);
}
int get(int id,int r,int l,int u,int v){
  if(r>v||l<u)return 0;
  if(r>=u&&l<=v){
    return st[id];
  }
  int mid=(r+l)>>1;
  return max(get(id<<1,r,mid,u,v),get(id<<1|1,mid+1,l,u,v));
}
  
}zz[3000];
void solve(){
  cin >> n >> k;
  memset(dp,-0x3f,sizeof dp);

  for(int i=1;i<=n;++i){
    cin >> a[i];
    s[i]=s[i-1]+a[i];
    
    }
  dp[0][0]=0;
  int ans=0;
  for(int i=1;i<=n;++i){
      for(int z=0;z<=min(k,i);++z){
        dp[i][z]=max(dp[i][z],dp[i-1][z]);
        if(z!=0)
        dp[i][z]=max(dp[i][z],zz[z-1].get(1,1,n,1,i-1)+s[i]);
        ans=max(ans,dp[i][z]);
        zz[z].update(1,1,n,i,dp[i][z]-s[i]);
      }
  }
  cout <<ans;
}
main()
{
  srand(time(0));
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    if(fopen(task".inp","r")){
      freopen(task".inp","r",stdin);
      freopen(task".out","w",stdout);
    }
    int t=1;
 //   cin >> t;
while(t--){
    solve();
    cout<<'\n';
}

}

Compilation message (stderr)

feast.cpp:81:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   81 | main()
      | ^~~~
feast.cpp: In function 'int main()':
feast.cpp:88:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |       freopen(task".inp","r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
feast.cpp:89:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |       freopen(task".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