Class 10 checkers

05week/checkers.js

@@ -8,13 +8,17 @@ const rl = readline.createInterface({
 });
 
 
-function Checker() {
+function Checker( color ) {
   // Your code here
+  // color = 'white' ? this.symbol = String.fromCharCode(0x125CB) : this.symbol = String.fromCharCode(0x125CF);
+  if( color == 'white' ) this.symbol = String.fromCharCode(0x125CF)
+  else this.symbol = String.fromCharCode(0x125CB);
 }
 
 class Board {
   constructor() {
     this.grid = []
+    this.checkers = []
   }
   // method that creates an 8x8 array, filled with null values
   createGrid() {
@@ -53,6 +57,36 @@ class Board {
   }
 
   // Your code here
+  createCheckers() {
+    // pieces are either black or white
+    let whitePosition = [
+      [0, 1], [0, 3], [0, 5], [0, 7],
+      [1, 0], [1, 2], [1, 4], [1, 6],
+      [2, 1], [2, 3], [2, 5], [2, 7]
+    ];
+
+    let blackPosition = [
+      [5, 0], [5, 2], [5, 4], [5, 6],
+      [6, 1], [6, 3], [6, 5], [6, 7],
+      [7, 0], [7, 2], [7, 4], [7, 6]
+    ];
+
+    for( let i = 0; i < 12; i++ ) {
+      let whiteChecker = new Checker( 'white' );
+      let whiteRow = whitePosition[i][0];
+      let whiteColumn = whitePosition[i][1];
+      this.checkers.push(whiteChecker);
+      this.grid[whiteRow][whiteColumn] = whiteChecker;
+    }
+
+    for( let i = 0; i < 12; i++ ) {
+      let blackChecker = new Checker( 'black' );
+      let blackRow = blackPosition[i][0];
+      let blackColumn = blackPosition[i][1];
+      this.checkers.push(blackChecker);
+      this.grid[blackRow][blackColumn] = blackChecker;
+    }
+  }
 }
 
 class Game {
@@ -61,7 +95,43 @@ class Game {
   }
   start() {
     this.board.createGrid();
+    this.board.createCheckers();
   }
+
+  moveChecker( start, end ) {
+    let startRow = parseInt(start[0]);
+    let startColumn = parseInt(start[1]);
+    let endRow = parseInt(end[0]);
+    let endColumn = parseInt(end[1]);
+
+    if( isValidInput(startRow, startColumn, endRow, endColumn) && isLegal(startRow, startColumn, endRow, endColumn) ) {
+      this.board.grid[endRow][endColumn] = this.board.grid[startRow][startColumn];
+      this.board.grid[startRow][startColumn] = null;
+
+      if( Math.abs(endRow - startRow) == 2 ) {
+        let killedRow = endRow - startRow > 0 ? startRow + 1 : endRow + 1;
+        let killedColumn = endColumn - startColumn > 0 ? startColumn + 1 : endColumn + 1;
+
+        this.board.grid[killedRow][killedColumn] = null;
+        let removeChecker = this.board.checkers.indexOf( this.board.grid[killedRow][killedColumn] );
+        this.board.checkers.splice( removeChecker, 1 );
+      }
+    }
+    else console.log( 'Try again with a legal move.' );
+  }
+}
+
+let isValidInput = function( startRow, startColumn, endRow, endColumn ) {
+  let validStart = ( startRow >= 0 && startRow <=8 ) && ( startColumn >= 0 && startColumn <= 8 );
+  let validEnd = ( endRow >= 0 && endRow <= 8 ) && ( endColumn >= 0 && endColumn <= 8 );
+  return ( validStart && validEnd );
+}
+
+let isLegal = function( startRow, startColumn, endRow, endColumn ) {
+  let rowDifference = Math.abs( endRow - startRow );
+  let columnDifference = Math.abs( endColumn - startColumn );
+  if( (rowDifference == 1 && columnDifference == 1) || (rowDifference == 2 && columnDifference == 2) ) return true;
+  else return false;
 }
 
 function getPrompt() {