Submission #551654

#	Time	Username	Problem	Language	Result	Execution time	Memory
551654		Carmel_Ab1	Split the sequence (APIO14_sequence)	C++17	100 / 100	1639 ms	86144 KiB

sequence

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
 */
#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int>vi;
typedef vector<vector<int>>vvi;
typedef vector<ll>vl;
typedef vector<vl> vvl;
typedef pair<int,int>pi;
typedef pair<ll,ll> pl;
typedef vector<pl> vpl;
typedef vector<ld> vld;
typedef pair<ld,ld> pld;
typedef vector<pi> vpi;

//typedef tree<ll, null_type, less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
template<typename T> ostream& operator<<(ostream& os, vector<T>& a){os<<"[";for(int i=0; i<ll(a.size()); i++){os << a[i] << ((i!=ll(a.size()-1)?" ":""));}os << "]\n"; return os;}

#define all(x) x.begin(),x.end()
#define YES out("YES")
#define NO out("NO")
#define out(x){cout << x << "\n"; return;}
#define outfl(x){cout << x << endl;return;}
#define GLHF ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define print(x){for(auto ait:x) cout << ait << " "; cout << "\n";}
#define pb push_back
#define umap unordered_map

template<typename T1, typename T2> istream& operator>>(istream& is, pair<T1, T2>& p){is >> p.first >> p.second;return is;}
template<typename T1, typename T2> ostream& operator<<(ostream& os, pair<T1, T2>& p){os <<"" << p.first << " " << p.second << ""; return os;}
void usaco(string taskname){
    string fin = taskname + ".in";
    string fout = taskname + ".out";
    const char* FIN = fin.c_str();
    const char* FOUT = fout.c_str();
    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);
}
template<typename T>
void read(vector<T>& v){
    int n=v.size();
    for(int i=0; i<n; i++)
        cin >> v[i];
}
template<typename T>
vector<T>UNQ(vector<T>a){
    vector<T>ans;
    for(T t:a)
        if(ans.empty() || t!=ans.back())
            ans.push_back(t);
    return ans;
}



void solve();
int main(){
    GLHF;
    int t=1;
    //cin >> t;
    while(t--)
        solve();
}
vl dp,prv,pref;

vvi opt;

void calc(int l,int r,int optl,int optr,int k){
    if(l>r)return;
    pl ans={-1,-1};

    int m=(l+r)/2;
    for(int i=optl; i<=min(m,optr); i++)
        ans=max(ans, {pref[m]*pref[i-1]-pref[i-1]*pref[i-1]+prv[i-1] ,i});

    opt[m][k]=ans.second;
    dp[m]=ans.first;
    calc(l,m-1,optl,ans.second,k);
    calc(m+1,r,ans.second,optr,k);
}

void solve() {
    int n,k;
    cin >> n >> k;
    vl a(n);
    read(a);

    reverse(all(a));
    a.pb(-1);
    reverse(all(a));

    assert(*max_element(all(a))<=1e4);

    pref.resize(n+1);
    opt.resize(n+1,vi(k+1,-1));

    for(int i=1; i<=n; i++)
        pref[i]=pref[i-1]+a[i];





    dp.resize(n+1);
    prv.resize(n+1);


    for(int j=1; j<=k; j++) {
        calc(1,n,1,n,j);
        prv=dp;
    }

    cout << dp[n] << "\n";

    int cur=n;
    for(int i=k; i>=1; i--){
        cout << opt[cur][i]-1 << " ";
        cur=opt[cur][i]-1;
    }
}
/*
 7 3
4 1 3 4 0 2 3
 */

Compilation message (stderr)

sequence.cpp: In function 'void usaco(std::string)':
sequence.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen(FIN, "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen(FOUT, "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~

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