Submission #721331

#	Time	Username	Problem	Language	Result	Execution time	Memory
721331		n0sk1ll	Split the sequence (APIO14_sequence)	C++14	100 / 100	1217 ms	81788 KiB

sequence

#include <bits/stdc++.h>

#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define mp make_pair
#define xx first
#define yy second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define all(x) x.begin(),x.end()
#define ff(i,a,b) for (int i = a; i < b; i++)
#define fff(i,a,b) for (int i = a; i <= b; i++)
#define bff(i,a,b) for (int i = b-1; i >= a; i--)
#define bfff(i,a,b) for (int i = b; i >= a; i--)

using namespace std;
long double typedef ld;
unsigned int typedef ui;
long long int typedef li;
pair<int,int> typedef pii;
pair<li,li> typedef pli;
pair<ld,ld> typedef pld;
vector<vector<int>> typedef graph;
unsigned long long int typedef ull;
//const int mod = 998244353;
const int mod = 1000000007;







//Note to self: Check for overflow

int a[100005];
li pre[100005];

li dp[2][100005];
int gde[204][100005];

li cost(int l, int r)
{
    return (pre[r]-pre[l-1])*(pre[r]-pre[l-1]);
}

void conq(int l, int r, int optl, int optr, bool cur, int k)
{
    if (l>r) return;
    int mid=(l+r)/2;

    dp[cur][mid]=(1ll<<61);
    int opt;
    fff(i,optl,min(mid-1,optr))
    {
        li sta=dp[!cur][i]+cost(i+1,mid);
        if (sta<dp[cur][mid]){
            dp[cur][mid]=sta;
            opt=i;
        }
    }

    //cout<<k<<" "<<mid<<": "<<opt<<endl;

    gde[k][mid]=opt;

    conq(l,mid-1,optl,opt,cur,k);
    conq(mid+1,r,opt,optr,cur,k);
}

void rekurz(int k, int n)
{
    if (k<2) return;
    rekurz(k-1,gde[k][n]);
    cout<<gde[k][n]<<" ";
}

int main()
{
    int n,k; cin>>n>>k; k++;
    fff(i,1,n) cin>>a[i];
    fff(i,1,n) pre[i]=pre[i-1]+a[i];

    bool cur=0;
    fff(i,1,n) dp[cur][i]=cost(1,i);
    fff(j,2,k) cur=!cur,conq(j,n,j-1,n,cur,j);

    li sum=0;
    fff(i,1,n) sum+=a[i];
    cout<<(sum*sum-dp[cur][n])/2<<"\n";
    rekurz(k,n);
}

//Note to self: Check for overflow

/*

7 3
4 1 3 4 0 2 3

7 6
4 1 3 4 0 2 3

4
-1 0
1 0
0 1
0 2

*/

Compilation message (stderr)

sequence.cpp: In function 'void conq(int, int, int, int, bool, int)':
sequence.cpp:69:9: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   69 |     conq(mid+1,r,opt,optr,cur,k);
      |     ~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29