Submission #7345339


Source Code Expand

#include <bits/stdc++.h>
using namespace std;
const int MOD=1e9+7;
//const int MOD=998244353;
const int INF=1e9;
const long long LINF=1e18;
#define int long long
//template
template <typename T>
void fin(T a){
  cout<<a<<endl;
  exit(0);
}
//main
signed main(){
  int N,M;cin>>N>>M;
  std::vector<int> v(N);
  for(int i=0;i<N;i++)cin>>v[i];
  if(M==1)fin(N/2);
  std::vector<int> w(M,0);
  for(int i=0;i<N;i++)w[v[i]%M]++;
  int ans=0;
  std::vector<int> use(M,0);
  for(int i=1;i<(M+1)/2;i++){
    int res=min(w[i],w[M-i]);
    ans+=res;use[i]+=res;use[M-i]+=res;
  }
  ans+=w[0]/2;
  if(M&1==0)ans+=w[M/2]/2;
  map<int,int> m;
  for(int i=0;i<N;i++)m[v[i]]++;
  std::vector<int> no(M);
  for(auto p:m)if(p.second&1)no[p.first%M]++;
  for(int i=0;i<M;i++)ans+=(w[i]-max(no[i],use[i]))/2;
  fin(ans);
}

Submission Info

Submission Time
Task D - Pair Cards
User drogskol
Language C++14 (GCC 5.4.1)
Score 0
Code Size 839 Byte
Status WA
Exec Time 66 ms
Memory 9600 KB

Judge Result

Set Name sample all
Score / Max Score 0 / 0 0 / 700
Status
AC × 2
AC × 19
WA × 15
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, sample-01.txt, sample-02.txt
Case Name Status Exec Time Memory
01-01.txt AC 1 ms 256 KB
01-02.txt AC 28 ms 1024 KB
01-03.txt WA 57 ms 4992 KB
01-04.txt WA 57 ms 4992 KB
01-05.txt WA 55 ms 4992 KB
01-06.txt WA 57 ms 4992 KB
01-07.txt WA 57 ms 4992 KB
01-08.txt WA 57 ms 4992 KB
01-09.txt WA 55 ms 4992 KB
01-10.txt WA 58 ms 5888 KB
01-11.txt WA 58 ms 7296 KB
01-12.txt AC 30 ms 1024 KB
01-13.txt AC 31 ms 2048 KB
01-14.txt WA 63 ms 7296 KB
01-15.txt AC 62 ms 7296 KB
01-16.txt WA 61 ms 7296 KB
01-17.txt AC 63 ms 7296 KB
01-18.txt AC 62 ms 7296 KB
01-19.txt AC 63 ms 7552 KB
01-20.txt AC 66 ms 9600 KB
01-21.txt WA 38 ms 1280 KB
01-22.txt WA 38 ms 1280 KB
01-23.txt WA 38 ms 1280 KB
01-24.txt WA 38 ms 1280 KB
01-25.txt AC 38 ms 2048 KB
01-26.txt AC 39 ms 3584 KB
01-27.txt AC 31 ms 6144 KB
01-28.txt AC 4 ms 2816 KB
01-29.txt AC 2 ms 1280 KB
01-30.txt AC 3 ms 2560 KB
sample-01.txt AC 1 ms 256 KB
sample-02.txt AC 1 ms 256 KB