Coding Dojo :: Diamond Print

problem.java

Input :: A
OutPut 
A


Input :: B
Output
 A
B B
 A

Input :: C
Output
  A
 B B
C   C
 B B
  A

Input :: D
Output
   A
  B B
 C   C
D     D
 C   C
  B B
   A

Input :: E
Output
    A
   B B
  C   C
 D     D
E       E
 D     D
  C   C
   B B
    A

step_01.java

==== DiamondTest.java ====

@Test
public void A_should_only_one() {
    Diamond p = new Diamond();
    assertEquals("A", p.create('A'));
}

==== Diamond.java ====

public class Diamond {
 
    public String create(char input) {
        return "A";
    }

}

step_02.java

==== DiamondTest.java ====

@Test
public void B_should_show_one_charecter() {
    assertEquals("AB", p.create('B'));
}


==== Diamond.java ====
public class Diamond {
 
    public String create(char input) {
        if(input == 'A'){
            return "A";
        }
        return "AB";
    }
}

step_03.java

==== Diamond.java ====
public class Diamond {
 
    public String create(char input) {
        String result = "";
        for(char start = 'A'; start<=input; start++) {
            result += start;
        }
        return result;
    }

}

step_04.java

==== DiamondTest.java ====

@Test
public void B_should_repeat_of_second_line() {
    assertEquals("ABB", p.create('B'));
}

==== Diamond.java ====
public class Diamond {
 
    public String create(char input) {
        String result = "";
        for(char start = 'A'; start<=input; start++) {
            result += start;
        }
        if(input != 'A') {
            result += input;
        }
        return result;
    }
}

step_05.java

==== DiamondTest.java ====

@Test
public void B_should_repeat_of_second_line() {
    assertEquals("ABBA", p.create('B'));
}

==== Diamond.java ====

public class Diamond {
 
    public String create(char input) {
        String result = "";
        for(char start = 'A'; start<=input; start++) {
            result += start;
        }
        if(input != 'A') {
            result += "BA";
        }
        return result;
    }
}

step_06.java

==== DiamondTest.java ====
@Test
public void A_should_only_one() {
    assertEquals("A\n", p.create('A'));
}

@Test
public void B_should_add_newline_of_every_line() {
        assertEquals("A\nBB\nA\n", p.create('B'));
}


==== Diamond.java ====
public class Diamond {
 
    public String create(char input) {
        String result = "";
        String bottomLine = "";
        for(char start = 'A'; start<=input; start++) {
            String line = ""+start;
            if( start != 'A' ) {
                line += input;
            }
            line += "\n";
            result += line;

            if( start != input ) {
                bottomLine = line + bottomLine;
            }
        }
        return result + bottomLine;
    }
}

step_07.java

==== Diamond.java ====
public class Diamond {
 
    public String create(char input) {
        String result = "";
        String bottomLine = "";
        for(char start = 'A'; start<=input; start++) {
            String line = buildLine(start, input);
            result += line;
            if( start != input ) {
                bottomLine = line + bottomLine;
            }
        }
        return result + bottomLine;
    }
 
    private String buildLine(char start, char input) {
        String line = ""+ start;
        if( start != 'A' ) {
            line += input;
        }
        line += "\n";
        return line;
    }
}

step_08.java

==== DiamondTest.java ====
@Test
public void B_should_add_spacebar_of_first_line() {
    assertEquals(" A\nB B\n A\n", p.create('B'));
}


==== Diamond.java ====
private String buildLine(char start, char input) {
    String line = "";
    if( start == 'A' ) {
        line = " " + start;
    } else {
        line = start + " " + start;
    }
    line += "\n";
    return line;
}

step_09.java

==== Diamond.java ====
private String buildLine(char start, char input) {
    String line = "";
    line += addSpace(input-start);
    line += start;
    if(start != 'A') {
        line += " " + start;
    }
    line += "\n";
    return line;
}
 
private String addSpace(int count) {
    String result = "";
    for(int i=0; i<count; i++) {
        result += " ";
    }
    return result;
}

step_10.java

==== DiamondTest.java ====
@Test
public void C_should_show_diamond() {
    String expectedResult = "  A\n"+
                            " B B\n"+
                            "C   C\n"+
                            " B B\n"+
                            "  A\n";
    assertEquals(expectedResult, p.create('C'));
}

step_11.java

==== Diamond.java ====
private String buildLine(char start, char input) {
    String line = "";
    line += addSpace(input-start);
    line += start;
    line += addRestOfLine(start);
    return line;
}
 
private String addSpace(int count) {
    String result = "";
    for(int i=0; i<count; i++) {
        result += " ";
    }
    return result;
}
 
private String addRestOfLine(char start) {
    String line = "";
    if(start != 'A') {
        int count = (start - 'A') * 2 - 1;
        return addSpace(count) + start + "\n";
    }
    return "\n";
}