Submission #1242052

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242052		Zero_OP	Safety (NOI18_safety)	C++17	100 / 100	50 ms	3752 KiB

safety

//CAUTION : this template is only suitable with C++17 (above) and home training, do not abuse when practicing offline
#include <bits/stdc++.h>

using namespace std;

//Benq inspires me lol
#define tcT template<class T
#define tcTU tcT, class U

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

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

tcT> int lwb(const vector<T>& a, const T& b){ return int(lower_bound(all(a), b) - begin(a)); }
tcT> int upb(const vector<T>& a, const T& b){ return int(upper_bound(all(a), b) - begin(a)); }

//loops (warning : ONLY for int)
#define rep(i, l, r) for(int i = (l); i < (r); ++i)
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)

#ifdef LOCAL
    #include "debug.h"
#else 
    #define debug(...) 42
#endif //LOCAL

//data types
using ll = long long;
using db = double;
using ld = long double;

using pi = pair<int, int>;
using pl = pair<ll, ll>;

using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
using vd = vector<db>;
using vc = vector<char>;
using vstr = vector<string>;

using vpi = vector<pi>;
using vpl = vector<pl>;

tcT> using min_heap = priority_queue<T, vector<T>, greater<T>>;
tcT> using max_heap = priority_queue<T>;

//bitwise operations
#define popcount(x) __builtin_popcountll(x) //count bits
#define BIT(k) (1LL << k) //bit k-th

//functions
tcT> bool minimize(T& a, const T& b){ if(a > b) return a = b, true; return false; } 
tcT> bool maximize(T& a, const T& b){ if(a < b) return a = b, true; return false; } 

tcT> T ceil_div(T a, T b){ return (a / b) + ((a ^ b) > 0 && a % b); }
tcT> T floor_div(T a, T b){ return (a / b) - ((a ^ b) < 0 && a % b); }

tcT> void safe_erase(vector<T>& a, T x){
    auto it = find(all(a), x);
    if(it != a.end()) a.erase(it);
}

#ifdef LOCAL //for checking time elapsed
const auto start_time = std::chrono::high_resolution_clock::now();
db time_elapsed(){ return chrono::duration<db>(std::chrono::high_resolution_clock::now() - 
                                               start_time).count(); }
#endif //LOCAL

void setIO(){
    ios_base::sync_with_stdio(0); cin.tie(0);
#define task "task"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        // freopen(task".out", "w", stdout);
    }
}

tcT> struct SlopeTrick{
    max_heap<T> L;
    min_heap<T> R;
    T min_f, shifted_L, shifted_R;

    SlopeTrick() : min_f(0), shifted_L(0), shifted_R(0), L(), R() {}

    //make sure l0 <= r0 
    void self_balance(){
        while(!L.empty() && !R.empty()){
            T l0 = L.top() + shifted_L;
            T r0 = R.top() + shifted_R;
            if(l0 <= r0) break;

            min_f += l0 - r0;
            L.pop(); R.pop();
            L.push(r0 - shifted_L);
            R.push(l0 - shifted_R);
        }
    }

    //add a function max(0, l - x)
    void add_linear_l(T l){
        L.push(l - shifted_L);
        self_balance();
    }

    //add a function max(0, x - r)
    void add_linear_r(T r){
        R.push(r - shifted_R);
        self_balance();
    }

    //add a function |x - a|
    void add_abs(T a){
        add_linear_l(a);
        add_linear_r(a);
    }

    void shift(T a){
        shifted_L += a;
        shifted_R += a;
    }

    T query(){
        return min_f;
    }

    void make_sliding_window(T a, T b){
        shifted_L += a;
        shifted_R += b;
    }

    void make_prefix_minimum(){
        min_heap<T>().swap(R);
    }

    void make_suffix_minimum(){
        max_heap<T>().swap(L);
    }
};

void testcase(int n_case){
    int N, H;
    cin >> N >> H;
    SlopeTrick<ll> st;
    rep(i, 0, N){
        int x; cin >> x;
        st.add_abs(x);
        st.make_sliding_window(-H, +H);
    }
    cout << st.min_f << '\n';
}

int main(){
    setIO();
    int T = 1; 
    // cin >> T;
    rep(i, 0, T) testcase(i);
#ifdef LOCAL
    cerr << '\n' << "Execution time : " << (time_elapsed() * 1000.0) << " ms";
#endif //LOCAL
    return 0;
}

Compilation message (stderr)

safety.cpp: In function 'void setIO()':
safety.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 5 / 5
• Subtask 5: 6 / 6
• Subtask 6: 11 / 11
• Subtask 7: 11 / 11
• Subtask 8: 22 / 22
• Subtask 9: 29 / 29