Submission #1054038

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054038		sleepntsheep	Diversity (CEOI21_diversity)	C++17	0 / 100	1 ms	2396 KiB

diversity

#include <cstdio>
#include <algorithm>
#define N 300001
#define A 300001

int o, n, q, a[N], fr[N], fr2[N];
long long z, y;

long long c2(int x) { return (x - 1ll) * x / 2ll; }

int main() {
  scanf("%d%d", &n, &q);
  for (int i = 1; i <= n; ++i) scanf("%d", a + i), ++fr[a[i]];

  for (int i = 1; i <= 300000; ++i)
    ++fr2[fr[i]];

  int sum = 0;
  for (int i = 1; i <= n; ++i)
    for (; fr2[i]--; )
      a[++o] = i, sum += i;

  for (int i = 1; i <= 10000; ++i) {
    int psum = 0;
    for (int j = 2; j <= o; psum += a[j++]) {
      int a_ = a[j - 1];
      int b_ = a[j];
      int x = psum - a_;
      int y = n - psum - b_;
      if (-c2(b_ + y + 1) -c2(a_ + x + 1) > -c2(b_ + x + 1) - c2(a_ + y + 1))
        std::swap(a[j], a[j - 1]);
    }
  }

  int psum = 0;
  for (int i = 1; i <= o; psum += a[i++]) {
    z += c2(n + 1) - c2(psum + 1) - c2(n - psum - a[i] + 1);
  }


  printf("%lld", z);

}

Compilation message (stderr)

diversity.cpp: In function 'int main()':
diversity.cpp:12:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |   scanf("%d%d", &n, &q);
      |   ~~~~~^~~~~~~~~~~~~~~~
diversity.cpp:13:37: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |   for (int i = 1; i <= n; ++i) scanf("%d", a + i), ++fr[a[i]];
      |                                ~~~~~^~~~~~~~~~~~~

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