Submission #972220

#	Time	Username	Problem	Language	Result	Execution time	Memory
972220		RaresFelix	The Potion of Great Power (CEOI20_potion)	C++17	38 / 100	3052 ms	236928 KiB

potion

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
 
using namespace std;
 
using ii = pair<int, int>;
using vi = vector<int>;
 
int n, rad;
int *H0, *A0, *B0;
vi Perm, Inv;
 

vector<vi> Snapshot;
vector<vi> Mare;
vector<vi> S;
 
void init(int N, int D, int H[]) {
    n = N;
    H0 = H;
    S.resize(n);
    Inv.resize(n);
    for(int i = 0; i < n; ++i)
        Perm.push_back(i);
    sort(Perm.begin(), Perm.end(), [&](auto a, auto b) {
        return H[a] < H[b];
    });
    for(int i = 0; i < n; ++i)
        Inv[Perm[i]] = i;
}

 
void curseChanges(int U, int A[], int B[]) {
    rad = min(U, 500);
    A0 = A;
    B0 = B;
    auto erase = [&](vi &V, int val) {
        vi Re;
        for(auto &it : V)
            if(it != val) Re.push_back(it);
        return Re;
    };
    vector<int> changed(n, 1);
    for(int nr = 0; nr < U; ++nr) {
        A[nr] = Inv[A[nr]];
        B[nr] = Inv[B[nr]];
    }
    for(int nr = 0; nr < U; ++nr) {
        if(nr % rad == 0) {
            vi cur;
            for(int i = 0; i < n; ++i) {
                if(changed[i]) {
                    cur.push_back(Mare.size());
                    Mare.push_back(S[i]);
                    changed[i] = 0;
                } else {
                    cur.push_back(Snapshot.back()[i]);
                }
            }
            Snapshot.push_back(cur);
        }
        int a = A[nr], b = B[nr];
        int ok = 0;
        for(auto it : S[a])
            if(it == b) ok = 1;
        changed[a] = 1;
        changed[b] = 1;
        if(ok)  {
            S[a] = erase(S[a], b);
            S[b] = erase(S[b], a);
        } else {
            S[b].push_back(a);
            S[a].push_back(b);
        }
    }
}
 
const int INF = 1e9;
 
int question(int x, int y, int v) {
    if(!v) {
        return INF;
    }
    --v;
    x = Inv[x];
    y = Inv[y];
    vi VSX = Mare[Snapshot[v / rad][x]];
    vi VSY = Mare[Snapshot[v / rad][y]];
    set<int> SX, SY;
    for(auto it : VSX) SX.insert(it);
    for(auto it : VSY) SY.insert(it);
    for(int i = v / rad * rad; i <= v; ++i) {
        int a = A0[i], b = B0[i];
        if(b == x) swap(a, b);
        if(a == x) {
            if(SX.count(b)) SX.erase(b);
            else SX.insert(b);
        }
        if(b == y) swap(a, b);
        if(a == y) {
            if(SY.count(b)) SY.erase(b);
            else SY.insert(b);
        }
    }

    vi VA, VB;
    for(auto it : SX)
        VA.push_back(H0[Perm[it]]);
    for(auto it : SY)
        VB.push_back(H0[Perm[it]]);

   // for(auto it : VA) cerr << it << " ";
   // cerr << "\n";
   // for(auto it : VB) cerr << it << " ";
   // cerr << "\n";
   // cerr << "\n";
    

    int p1 = 0, p2 = 0;
    int re = INF;
    while(p1 < VA.size() && p2 < VB.size()) {
        re = min(re, abs(VB[p2] - VA[p1]));
        if(VA[p1] < VB[p2]) ++p1;
        else ++p2;
    }

    return re;
}

Compilation message (stderr)

potion.cpp: In function 'int question(int, int, int)':
potion.cpp:122:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |     while(p1 < VA.size() && p2 < VB.size()) {
      |           ~~~^~~~~~~~~~~
potion.cpp:122:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |     while(p1 < VA.size() && p2 < VB.size()) {
      |                             ~~~^~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 17 / 17
• Subtask 3: 0 / 14
• Subtask 4: 0 / 18
• Subtask 5: 21 / 21
• Subtask 6: 0 / 30