Submission #500014

#	Time	Username	Problem	Language	Result	Execution time	Memory
500014		Carmel_Ab1	Split the sequence (APIO14_sequence)	C++17	33 / 100	527 ms	131076 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();
}

struct seg{
    ll l,r,m;
    seg* lp=0,*rp=0;
    vl ln;

    seg(ll l,ll r):l(l),r(r),m((l+r)/2){ln={ll(-1e9),ll(-1e9),ll(-1e9)};}



    ll get(vl& v,ll x){return v[0]*x+v[1];}

    void upd(vl f){
        bool lef=get(f,l)>get(ln,m);
        bool mid=get(f,m)>get(ln,m);

        if(mid)
            swap(f,ln);
        if(l+1==r)return;

        if(lef!=mid) {
            if(!lp)lp=new seg(l,m);
            lp->upd(f);
        }
        else {
            if(!rp)rp=new seg(m,r);
            rp->upd(f);
        }
    }

    pl qur(ll x) {
        if (l + 1 == r)return {get(ln,x), ln[2]};
        if (x < m) {
            if (!lp)lp = new seg(l, m);
            return max(lp->qur(x), {get(ln,x), ln[2]});
        }
        else{
            if(!rp)rp=new seg(m,r);
            return max(rp->qur(x), {get(ln,x), ln[2]});
        }
    }

};
void solve() {
    int n,k;
    cin >> n >> k;
    vl a(n+1);
    for(int i=1; i<=n; i++)
        cin >> a[i];

    vl pref(n+1);
    for(int i=0; i<=n; i++)
        pref[i]=(i?pref[i-1]:0)+a[i];

    vvl dp(n+1,vl(k+1)),prv(n+1,vl(k+1,1));



    vector<seg*>s(k+1);
    for(int i=0; i<=k; i++)
        s[i]=new seg(0,1e9);

    for(int i=1; i<=n; i++) {
        for (int j = 1; j <= k; j++) {
            pl p=s[j]->qur(pref[i]);
            dp[i][j] = p.first,prv[i][j]=p.second;
        }
        for(int j=0; j<=k; j++)
            if (i != n)
                s[j]->upd({pref[i], -pref[i] * pref[i] + (j?dp[i][j-1]:0),i});
    }

    cout << dp[n][k] << "\n";
    int i=n,j=k;
    vi ans;

    while(i && j){
        ans.pb(prv[i][j]);
        i=prv[i][j];
        j--;
    }
    sort(all(ans));
    ans=UNQ(ans);
    print(ans)

}
/*
 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: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29