Added question 30

Author: onufryk

src/com/onufryk/exercise/Question030.java

@@ -0,0 +1,61 @@
+package com.onufryk.exercise;
+
+public class Question030 {
+	private char[][] matrix = { 
+			{ 'a', 'b', 'c', 'e' }, 
+			{ 's', 'f', 'c', 's' }, 
+			{ 'a', 'd', 'e', 'e' } };
+	private int rows = 3;
+	private int cols = 4;
+	private Boolean[][] visited = new Boolean[rows][cols];
+	private int pathLength = 0;
+
+	public Boolean containsPath(String str) {
+		if (this.matrix == null || this.rows < 1 || this.cols < 1 || str == null) {
+			return false;
+		}
+		this.pathLength = 0;
+		for (int row = 0; row < this.rows; row++) {
+			for (int col = 0; col < this.cols; col++) {
+				this.visited[row][col] = false;
+			}
+		}
+		for (int row = 0; row < this.rows; row++) {
+			for (int col = 0; col < this.cols; col++) {
+				if (this.containsPath(str, row, col)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	private Boolean containsPath(String str, int row, int col) {
+		if (this.pathLength == str.length()) {
+			return true;
+		}
+		Boolean hasPath = false;
+
+		if (row >= 0 && row < this.rows && col >= 0 && col < this.cols
+				&& this.matrix[row][col] == str.charAt(this.pathLength) && !this.visited[row][col]) {
+			this.pathLength++;
+			this.visited[row][col] = true;
+			hasPath = this.containsPath(str, row, col - 1) || this.containsPath(str, row - 1, col)
+					|| this.containsPath(str, row, col + 1) || this.containsPath(str, row + 1, col);
+			if (!hasPath) {
+				this.pathLength--;
+				this.visited[row][col] = false;
+			}
+		}
+
+		return hasPath;
+	}
+
+	public static void main(String[] args) {
+		Question030 app = new Question030();
+		System.out.println(app.containsPath("bcced"));
+		System.out.println(app.containsPath("abcb"));
+		System.out.println(app.containsPath("abceseedasfc"));
+	}
+
+}