Submission #724723

#	Time	Username	Problem	Language	Result	Execution time	Memory
724723		bLIC	Split the sequence (APIO14_sequence)	C++17	100 / 100	501 ms	84968 KiB

sequence

/**
 *  Author: Anil Byar
**/

#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;

// template<class T>
// using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;



#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)(x).size()
#define uniq(v) v.erase(unique(all(v)), v.end())
#define ft first
#define sd second
#define pb push_back

// Source: https://codeforces.com/blog/entry/68809
// { start
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
// } end


typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
typedef vector<vl> vvl;

#define dbg if(0)

const ll MOD = 1e9+7;
const ll MOD9 = 998244353;
const ll INFLL = 1e18+5;
const int INF = 1e9;

void printbit(int x, int len) {string s="\n";while(len--){s=((x%2)?'1':'0')+s;x/=2;} cout<<s;}
ll power(ll x, ll y, ll mod){if (y==0) return 1;ll ret = power(x, y/2, mod);ret *= ret;ret%=mod;if (y&1) ret *= x;return ret%mod;}
ll modinv(ll x, ll mod = MOD) {return power(x, mod-2, mod);}

template<class T>
istream& operator>>(istream&in, vector<T>&v){
    for (T& x:v) in>>x;
    return in;
}
template<class T>
ostream& operator<<(ostream&out, vector<T>&v){
    for (T& x:v) out<<x<<' ';
    cout<<'\n';
    return out;
}
// use ?: with brackets (?:)
// check for overflow
// think about dp
// Read the statement carefully


struct Line{
    ll m, c, id;
    Line(ll mm, ll cc, int idd):m(mm), c(cc), id(idd){}
    Line(){m = 0;c=0;id=0;}
    ll at(ll x){
        return m*x+c;
    }
    friend ostream& operator<<(ostream&out, const Line& l){
        out<<l.m<<"x + "<<l.c<<' ';
        return out;
    }
};

double intersection(const Line& l1, const Line& l2) {
    return (l2.c-l1.c)/(double)(l1.m-l2.m);
}

bool order1(const Line& l1, const Line& l2, ll x){
    return x*(l2.m-l1.m)>=l1.c-l2.c;
}
bool order2(const Line& l1, const Line& l2, const Line& l3){
    return (l1.c-l2.c)*(l3.m-l2.m)>=(l2.c-l3.c)*(l2.m-l1.m);
}

#define sq(x) ((x)*(x))

const int maxN = 1e5+5; // change this
const int maxK = 8001;


void solve(){
    int N, K;cin>>N>>K;
    ll A[N], P[N+1]{};
    for (int i = 0;i<N;i++) cin>>A[i], P[i+1] = P[i] + A[i];

    vl dp1(N+1), dp2(N+1);
    int prev[N+1][K+1];
    memset(prev, 0, sizeof(prev));
    for (int k = 1;k<=K;k++){

        Line d[N+1];
        int l = 0, r = 0;
        d[0] = Line();

        for (int i = 1;i<=N;i++){
            while(r-l>0 && order1(d[l], d[l+1], P[i])) l++;
            dp2[i] = d[l].at(P[i]);
            prev[i][k] = d[l].id;
            Line curr(P[i], dp1[i] - sq(P[i]), i);
            while(r-l>0 && order2(d[r-1], d[r], curr)){
                r--;
            }
            // if (k==K) cout<<curr<<endl;
            r++;
            d[r] = curr;
        }
        swap(dp1, dp2);
    }
    cout<<dp1[N]<<'\n';
    vi ans;
    while(K) {
        ans.push_back(prev[N][K]);
        N = prev[N][K];
        K--;
    }
    reverse(all(ans));
    cout<<ans;
    return;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

#define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
    freopen("debug.dbg", "w", stderr);
    int tt = clock();
#endif

    int t=1, i = 1;
    // cin>>t;
    while(t--){
        // cout<<"Case #"<<i++<<": ";
        solve();
        cout<<"\n"[t!=0];
    }
#ifndef ONLINE_JUDGE
    cerr << "TIME = " << (float)(clock() - tt)/CLOCKS_PER_SEC << endl;
    tt = clock();
#endif
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:178:14: warning: unused variable 'i' [-Wunused-variable]
  178 |     int t=1, i = 1;
      |              ^

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