Making The Road Wiki

/* P.128 */
void distribution_count (int a[], int N, int M = 100) {
  int count[M+1]; /* 0 ~ M */
  int b[N+1];
  memset(count, 0, sizeof(count));
  for (int i = 1; i <= N; i++) count[a[i]]++;
  for (int i = 1; i <= M; i++) count[i] += count[i-1];
  for (int i = N; i >= 1; i--) b[count[a[i]]--] = a[i];
  memcpy(a, b, sizeof(b));
}