Submission #995054


Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)
#define all(c) (c).begin(), (c).end()
#define zero(a) memset(a, 0, sizeof a)
#define minus(a) memset(a, -1, sizeof a)
#define watch(a) { cout << #a << " = " << a << endl; }
template<class T1, class T2> inline bool minimize(T1 &a, T2 b) { return b < a && (a = b, 1); }
template<class T1, class T2> inline bool maximize(T1 &a, T2 b) { return a < b && (a = b, 1); }

typedef long long ll;
int const inf = 1<<29;

namespace tree {
struct union_find {
  vector<int> par, rank, size;
  int compnum;

  union_find(int N) {
    compnum = N;
    par.resize(N), rank.resize(N), size.resize(N);
    for(int i=0; i<N; i++) {
      par[i] = i;
      rank[i] = 0;
      size[i] = 1;
    }
  }

  int root(int x) {
    return par[x] == x ? x : par[x] = root(par[x]);
  }

  void unite(int x, int y) {
    x = root(x), y = root(y);
    if(x == y) return;
    if(rank[x] < rank[y]) {
      par[x] = y, size[y] += size[x];
    } else {
      par[y] = x, size[x] += size[y];
      if(rank[x] == rank[y]) rank[x]++;
    }
    compnum--;
  }

  int operator[](int x) { return root(x); }
  void operator()(int x, int y) { return unite(x, y); }

  bool same(int x, int y) { return root(x) == root(y); }
  int size_of(int x) { return size[root(x)]; }
  int num_of_comps() { return compnum; }
};
}

int main() {

  int N, M; cin >> N >> M;
  vector<int> X(N);
  rep(i, N) {
    cin >> X[i];
  }

  sort(all(X));

  tree::union_find uf(N);

  // 元のindexが同じUFをする
  rep(i, N - 1) {
    if(X[i] == X[i + 1]) {
      uf(i, i + 1);
    }
  }

  map<int, int> st;

  // MODが同じ数で、元の値ごとに、数の総数が奇数かどうかを調べる。
  unordered_map<int, unordered_map<int, bool>> odd;
  rep(i, N) {
    odd[X[i] % M][X[i]] ^= 1;
    // Mでmodをとり
    X[i] %= M;
    // 端数の一致する対称を詰める
    st[(M - X[i]) % M] ++;
  }

  unordered_map<int, int> oddcnt;
  for(auto const& e: odd) {
    int ocnt = 0;
    for(auto const& u: e.second) {
      if(u.second) ocnt++;
    }
    oddcnt[e.first] = ocnt;
  }

  ll ans = 0;

  unordered_map<int, int> selectedXCnt;

  rep(i, N) {
    auto tmp = (M - X[i]) % M;

    if(st[tmp] == 0) continue;

    // 自分は選んだので消す
    st[tmp]--;

    // 自分の端数対称が一致するものを見つけては消す
    if(st[X[i]] > 0) {
      selectedXCnt[X[i]]++;
      st[X[i]]--;
      ans ++;
    }
    else {
      // 復活
      st[tmp]++;
    }
  }

  for(auto const& e: st) {
    auto x = e.first;
    auto a = oddcnt[x];
    auto b = selectedXCnt[x];
    ans += (e.second - max(0, b*2 - a)) / 2;
  }

  cout << ans << endl;
  
  return 0;
}

Submission Info

Submission Time
Task D - Pair Cards
User motxx
Language C++14 (GCC 5.4.1)
Score 0
Code Size 2889 Byte
Status WA
Exec Time 167 ms
Memory 29732 KB

Judge Result

Set Name sample all
Score / Max Score 0 / 0 0 / 700
Status
AC × 1
WA × 1
AC × 14
WA × 18
Set Name Test Cases
sample sample-01.txt, sample-02.txt
all sample-01.txt, sample-02.txt, 01-01.txt, 01-02.txt, 01-03.txt, 01-04.txt, 01-05.txt, 01-06.txt, 01-07.txt, 01-08.txt, 01-09.txt, 01-10.txt, 01-11.txt, 01-12.txt, 01-13.txt, 01-14.txt, 01-15.txt, 01-16.txt, 01-17.txt, 01-18.txt, 01-19.txt, 01-20.txt, 01-21.txt, 01-22.txt, 01-23.txt, 01-24.txt, 01-25.txt, 01-26.txt, 01-27.txt, 01-28.txt, 01-29.txt, 01-30.txt
Case Name Status Exec Time Memory
01-01.txt AC 3 ms 256 KB
01-02.txt WA 53 ms 5260 KB
01-03.txt WA 55 ms 5004 KB
01-04.txt WA 54 ms 4480 KB
01-05.txt WA 56 ms 5120 KB
01-06.txt WA 57 ms 4480 KB
01-07.txt WA 59 ms 4608 KB
01-08.txt WA 76 ms 4864 KB
01-09.txt WA 77 ms 4992 KB
01-10.txt WA 109 ms 13964 KB
01-11.txt WA 160 ms 23076 KB
01-12.txt AC 39 ms 1792 KB
01-13.txt AC 39 ms 1792 KB
01-14.txt AC 54 ms 5912 KB
01-15.txt AC 56 ms 6144 KB
01-16.txt AC 61 ms 6400 KB
01-17.txt AC 73 ms 6656 KB
01-18.txt AC 76 ms 6656 KB
01-19.txt AC 85 ms 8704 KB
01-20.txt AC 167 ms 29732 KB
01-21.txt WA 44 ms 2048 KB
01-22.txt WA 44 ms 1920 KB
01-23.txt WA 46 ms 1920 KB
01-24.txt WA 50 ms 2304 KB
01-25.txt WA 54 ms 3200 KB
01-26.txt WA 55 ms 3328 KB
01-27.txt AC 103 ms 21436 KB
01-28.txt AC 9 ms 1536 KB
01-29.txt WA 4 ms 512 KB
01-30.txt AC 3 ms 256 KB
sample-01.txt WA 2 ms 256 KB
sample-02.txt AC 2 ms 256 KB