Allstate NI Coding Competition — Challenge 1
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import java.util.Arrays;
/**
* The Connect4 class is a basic simulator for the popular
* Connect4 game where opposing players alternately
* drop a coloured counter into a 6 x 7 grid seeking
* to achieve 4 of their counters resting in a horizontal,
* vertical or diagonal row before their opponent.
*
* In game play, rows and columns are always
* referenced 1-6 or 1-7 appropriately
* @version 1.0, Apr 2021
*/
1 public class Connect4 {
2 private final char[][] gameBoard = {
3 {'0', '0', '0', '0', '0', '0', '0'}, //Row 1, Bottom
4 {'0', '0', '0', '0', '0', '0', '0'}, //Row 2
5 {'0', '0', '0', '0', '0', '0', '0'}, //Row 3
6 {'0', '0', '0', '0', '0', '0', '0'}, //Row 4
7 {'0', '0', '0', '0', '0', '0', '0'}, //Row 5
8 {'0', '0', '0', '0', '0', '0', '0'} //Row 6, Top
/** @param counter - A single character denoting the colour of the counter played
* @param col - The number of the column into which the counter is played - relative from 1 */
9 public void playCounter(final char counter, final int col) {
10 for(int row = 1; row <= gameBoard.length; row++) {
11 if(isSlotEmpty(col, row)) {
12 gameBoard[row-1][col-1] = counter;
13 return;
14 }
15 }
16 }
/**
*
* @return - A boolean value indicating if the last move has won the game
*/
17 public boolean isGameWon() {
18 if(fourInARowHorizontally()) return true;
19 if(fourInARowVertically()) return true;
20 if(fourInARowDiagonallyLeftToRight()) return true;
21 if(fourInARowDiagonallyRightToLeft()) return true;
22 return false;
23 }
24 public char getCounter(final int col, final int row) {
25 return gameBoard[row-1][col-1];
26 }
27 private boolean isSlotEmpty(final int col, final int row) {
28 return getCounter(col, row) == '0';
29 }
30 private boolean fourInARowHorizontally() {
31 for(int row = 1; row <= gameBoard.length; row++) {
32 int numInARow = 1;
33 for(int col = 1; col <= gameBoard[row-1].length-1; col++) {
34 if(isSlotEmpty(col, row)) {
35 numInARow = 1;
36 } else if(getCounter(col, row) == getCounter(col+1, row)) {
37 numInARow++;
38 if(numInARow == 4) return true;
39 } else
40 numInARow = 1;
41 }
42 }
43 return false;
44 }
45 private boolean fourInARowVertically() {
46 for(int col = 1; col <= gameBoard[0].length; col++) {
47 int numInARow = 1;
48 for(int row = 1; row <= gameBoard.length; row++) {
49 if(isSlotEmpty(col, row)) {
50 numInARow = 1;
51 } else if(getCounter(col, row) == getCounter(col, row+1)) {
52 numInARow++;
53 if(numInARow == 4) return true;
54 } else
55 numInARow = 1;
56 }
57 }
58 return false;
59 }
60 private boolean fourInARowDiagonallyLeftToRight() {
61 for(int row = 1; row <= 3; row++) {
62 for(int col = 1; col <= 4; col++) {
63 if(!isSlotEmpty(col, row)) {
64 if((getCounter(col, row) == getCounter(col+1, row+1))
65 && (getCounter(col+1, row+1) == getCounter(col+2, row+2))
66 && (getCounter(col+2, row+2) == getCounter(col+3, row+3))
67 ) return true;
68 }
69 }
70 }
71 return false;
72 }
73 private boolean fourInARowDiagonallyRightToLeft() {
74 for(int row = 1; row <= 3; row++) {
75 for(int col = 4; col <= 7; col++) {
76 if(!isSlotEmpty(col, row)) {
77 if((getCounter(col, row) == getCounter(col-1, row+1))
78 && (getCounter(col-1, row+1) == getCounter(col-2, row+2))
79 && (getCounter(col-2, row+2) == getCounter(col-3, row+3))
80 ) return true;
81 }
82 }
83 }
84 return false;
85 }
86 }
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