京东第一题合唱团ac代码，求大佬给一下第二题男女关系解答思路

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);  int N = in.nextInt();  int[] arr = new int[N];  for (int i = 0; i < N; i++) {
        arr[i] = in.nextInt();
    }  int[] sorted = new int[N];
    System.arraycopy(arr, 0, sorted, 0, N);
    Arrays.sort(sorted);  int num = 1;  int left = 0;  for (int i = 0; i < N; i++) {  if ((i != N - 1) && arrEqual(arr, sorted, left, i)) {
            num++;
            left = i + 1;
        }
    }
    System.out.print(num);
} public static boolean arrEqual(int[] arr, int[] sorted, int left, int right) 
    {  int[] help1 = new int[right - left + 1];
    System.arraycopy(arr, left, help1, 0, right - left + 1);
    Arrays.sort(help1);  for (int i = 0; i < right - left + 1; i++) {  if (help1[i] != sorted[left + i]) {  return false;
        }
    }  return true;
}