Submission #696508

#	Time	Username	Problem	Language	Result	Execution time	Memory
696508		cig32	Diversity (CEOI21_diversity)	C++17	64 / 100	49 ms	6756 KiB

diversity

#include "bits/stdc++.h"
using namespace std;
#define int long long
const int MAXN = 2e5 + 10;
const int MOD = 1e9 + 7;
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
int bm(int b, int p) {
  if(p==0) return 1 % MOD;
  int r = bm(b, p >> 1);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
int inv(int b) { 
  return bm(b, MOD-2);
}
int fastlog(int x) {
  return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void printcase(int i) { cout << "Case #" << i << ": "; }
void solve(int tc) {
  int n, q;
  cin >> n >> q;
  int c = 300000;
  int freq[c+1];
  for(int i=1; i<=c; i++) freq[i] = 0;
  for(int i=1; i<=n; i++) {
    int x;cin >> x;freq[x]++;
  }
  sort(freq+1, freq+c+1);
  int a[n+1];
  int l=1,r=n,ct=0;
  deque<int> dq;
  stack<int> y; queue<int> x;
  for(int i=1;i<=c; i++) {
    if(freq[i]>0) {
      if(ct&1) {
        y.push(freq[i]);
      }
      else {
        x.push(freq[i]);
      }
      ct^=1;
    }
  }
  while(x.size()) {
    dq.push_back(x.front()); x.pop();
  }
  while(y.size()) {
    dq.push_back(y.top()); y.pop();
  }
  int m=dq.size();
  int ans=0;
  int ws=0,rs=0;
  for(int i=m-1; i>=0; i--) {
    ans += dq[i] * ws - dq[i] * (i-1) * rs;
    ws += dq[i] * i, rs += dq[i];
  }
  for(int i=0; i<m; i++) ans += dq[i] * (dq[i] + 1) / 2;
  cout << ans << "\n";

}
int32_t main() {
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}

Compilation message (stderr)

diversity.cpp: In function 'void solve(long long int)':
diversity.cpp:33:7: warning: unused variable 'a' [-Wunused-variable]
   33 |   int a[n+1];
      |       ^
diversity.cpp:34:7: warning: unused variable 'l' [-Wunused-variable]
   34 |   int l=1,r=n,ct=0;
      |       ^
diversity.cpp:34:11: warning: unused variable 'r' [-Wunused-variable]
   34 |   int l=1,r=n,ct=0;
      |           ^

• Subtask 1: 4 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 26 / 26
• Subtask 6: 0 / 36