// Implement a String class which will store the String as an array of chars
// As the MyString will be immutable, make the array be exactly equal to the size of the String
// include methods of:  toString (to print it out), replace, length, split, toLowerCase, toUpperCase 

public class MyString
{
	private char[] string;
	
	public MyString()						// no arg constructor, no String to create
	{
		string = null;	
	}	
		
	public MyString(String s)				// copy each character of s into an array element
	{
		string = new char[s.length()];
		for(int i=0;i<s.length();i++)
			string[i] = s.charAt(i);
	}
	
	public MyString(char[] c)				// copy each character of c into string
	{
		string = new char[c.length];
		for(int i=0;i<c.length;i++)
			string[i] = c[i];
	}
	
	public String toString()				// create a String temp which will be each character of string added to it
	{
		String temp="";
		for(int i=0;i<string.length;i++)
			temp+=string[i];
		return temp;
	}
	
	public String toUpperCase()				// like toString but upper case any Character that is a letter before adding it to temp
	{
		String temp="";
		for(int i=0;i<string.length;i++)
			temp+=Character.toUpperCase(string[i]);
		return temp;
	}

	public String toLowerCase()				// like toString but lower case any Character that is a letter before adding it to temp
	{
		String temp="";
		for(int i=0;i<string.length;i++)
			temp+=Character.toLowerCase(string[i]);
		return temp;
	}

	public String replace(char a, char b)	// like toString but before adding each character of string to temp, if it equals a change it to b
	{
		String temp="";
		for(int i=0;i<string.length;i++)
			if(string[i]==a) temp+=b;
			else temp+=string[i];
		return temp;
	}
	
	public int length()						// our array, string, has 1 char per character in the String, so return string's length
	{
		return string.length;
	}
	
	public String[] split()					// use ' ' for the delimiter, note:  this code does not work correctly if we have two or more blanks in a row
	{											// to use a different delimiter, write a method that receives a char, c, and tests if(string[i]!=c) instead of if(string[i]!=' ')
		String temp="";						// accumulate the characters of the current word until you reach a ' '
		String[] strings = new String[100];					// assume we won't need more than 100 of these, we could conceivably use string.length/2+1 as our bounding factor instead
		int count=0;						// used to index into the strings array
		for(int i=0;i<string.length;i++)
			if(string[i]!=' ')				// until we find a ' ', add the current char to temp
				temp+=string[i];
			else							// once we have found a ' ', end this word by adding temp to the strings array, reset temp to "" and increment count for the next item in the strings array
			{
				strings[count] = temp;					
				count++;
				temp="";
			}
		String[] strings2 = new String[count];		// create an array whose size is equal to the number of distinct strings found in our string
		for(int i=0;i<count;i++)					// copy each string into the new array
			strings2[i] = strings[i];
		return strings2;					// return the smaller array
	}
}