public class Exercise6
{
  public static void main(String[] args)
  {
    // test calls here
  }

  public static int maximumPosition1(int[] a)
  {
    int m = 0;
    int n = a.length;
    for (int i = 0; i < n; i++)
    {
      if (a[i] > a[m]) m = i;
    }
    return m;
  }

  public static int maximumPosition2(int[] a)
  {
    if (a == null) return -1;
    int m = 0;
    int n = a.length;
    for (int i = 0; i < n; i++)
    {
      if (a[i] > a[m]) m = i;
    }
    return m;
  }

  public static int maximumElement(int[] a)
  {
    int m = 0;
    int n = a.length;
    for (int i = 0; i < n; i++)
    {
      if (a[i] > m) m = a[i];
    }
    return m;
  }

  public static int[] insert(int[] a, int p, int n, int x)
  {
    int m = a.length;
    int[] b = new int[m+n];
    for (int i = 0; i <= p; i++)
      b[i] = a[i];
    for (int i = 0; i < n; i++)
      b[p+i] = x;
    for (int i = p; i < m; i++)
      b[n+i] = a[i];
    return b;
  }

  public static int[] remove(char[] a, char x)
  {
    int n = a.length;
    int c = 0;
    for (int i = 0; i < n; i++)
    {
      if (a[i] == x) c = c+1;
    }
    int[] b = new int[n-c];
    int p = 0;
    for (int i = 0; i < n; i++)
    {
      if (a[i] != x) 
      {
        b[p] = a[i];
        p = p+1;
      }
    }
    return b;
  }

  public static boolean substitute(int[] a, int[] p, int[] x)
  {
    boolean invalid = false;
    int n = p.length;
    for (int i = 0; i < n; i++)
    {
      int p0 = p[i];
      if (0 <= p0 && p0 < a.length) 
        a[p0] = x[i];
      else
        invalid = true;
    }
    return invalid;
  }

  public static class InvalidArgument extends Exception 
  { 
    public int pos;
    public InvalidArgument(int pos) { this.pos = pos; }
  }

  public static void substitute2(int[] a, int[] p, int[] x)
    throws InvalidArgument
  {
    int n = p.length;
    for (int i = 0; i < n; i++)
    {
      int p0 = p[i];
      if (p0 < 0 || p0 >= a.length) throw new InvalidArgument(p0);
      a[p0] = x[i];
    }
  }
}