Submission #1156942

#	Time	Username	Problem	Language	Result	Execution time	Memory
1156942		Zero_OP	Boxes with souvenirs (IOI15_boxes)	C++20	100 / 100	508 ms	196100 KiB

boxes

#include <bits/stdc++.h>

using namespace std;

//loops (warning : long long)
#define FOR(i, l, r) for(int i = (l); i < (r); ++i)
#define ROF(i, r, l) for(int i = (r - 1); i >= l; --i)

//pairs, tuples
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second

//vectors
#define all(v) begin(v), end(v)
#define rall(v) rbegin(v), rend(v)
#define pb push_back
#define eb emplace_back
#define sum_of(v) accumulate(all(v), 0ll)
#define sz(v) (int)v.size()
#define compact(v) v.erase(unique(all(v)), end(v))

//binary search
#define lwb lower_bound
#define upb upper_bound

//other stuffs
#define dbg(x) "[" #x " = " << (x) << "]"
#define file(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }

template<typename T>
bool minimize(T& a, const T& b){
    if(a > b) return a = b, true;
    return false;
}

template<typename T>
bool maximize(T& a, const T& b){
    if(a < b) return a = b, true;
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using db = double;
using pi = pair<int, int>;
using pl = pair<ll, ll>;

using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vpi = vector<pi>;
using vpl = vector<pl>;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll delivery(int N, int K, int L, int p[]){
    int mid = L >> 1;

    sort(p, p+N);
    vl pref(N+1);
    
    FOR(i, 0, N){
        int j = max(0, i - K + 1);
        ll cur = (j > 0 ? pref[j-1] : 0);
        if(p[j] <= mid && p[i] > mid){
            cur += L;
        } else if(p[j] <= mid && p[i] <= mid){
            cur += p[i] * 2;
        } else{
            cur += (L - p[j]) * 2;
        }

        pref[i] = cur;
    }

    vl suff(N+1);
    ROF(i, N, 0){
        int j = min(N, i+K) - 1;
        ll cur = suff[j+1];
        if(p[i] <= mid && p[j] > mid){
            cur += L;
        } else if(p[i] <= mid && p[j] <= mid){
            cur += p[j] * 2;
        } else{
            cur += (L - p[i]) * 2;
        }

        suff[i] = cur;
    }

    ll ans = min(pref[N-1], suff[0]);
    FOR(i, 0, N-1){
        minimize(ans, pref[i] + suff[i+1]);
    }

    return ans;
}

#ifdef LOCAL
int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

    freopen("in.txt", "r", stdin);
    
    int N, K, L;
    cin >> N >> K >> L;
    int position[N];
    FOR(i, 0, N) cin >> position[i];
    cout << delivery(N, K, L, position) << '\n';

    return 0;
}
#endif 

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30