public class Q1Number { /** * This question is about a number finding puzzle. * * You will be given a square grid of numbers, represented as a single * array of integers. Each value in the grid is a number between 0 and 9. * You will also be given a target number. Your task is to try to find * the target number within the grid. If you find it, you return the * index of the grid element holding the first digit of the number. If * you can't find it, return -1. * * Numbers can be 'hidden' in the grid by consecutive digits being in * horizontally or vertically adjacent elements (but not diagonally). * When creating numbers, digits in the grid may only be used ONCE. * * For example, given the 3 x 3 grid [2, 4, 4, 0, 5, 7, 7, 1, 4] and the * target 42, you would return 1. Visualizing the grid: * * 2 4 4 * 0 5 7 * 7 1 4 * * 2 4 _ * _ _ _ * _ _ _ * * The number 42 is 'hidden' in the first two elements of the grid, starting * at offset 1 then going left, so the answer is 1. * * Given the 6 x 6 grid [0, 8, 0, 9, 1, 1, 6, 7, 6, 3, 2, 9, 2, 7, 7, 9, 2, 8, 4, 0, 9, 2, 9, 2, 0, 5, 1, 1, 5, 9, 8, 5, 7, 1, 1, 7], * and the target 91507, you would return 20. Visualizing the grid: * * 0 8 0 9 1 1 * 6 7 6 3 2 9 * 2 7 7 9 2 8 * 4 0 9 2 9 2 * 0 5 1 1 5 9 * 8 5 7 1 1 7 * * _ _ _ _ _ _ * _ _ _ _ _ _ * _ 7 _ _ _ _ * _ 0 9 _ _ _ * _ 5 1 _ _ _ * _ _ _ _ _ _ * * The number 91507 is 'hidden' in the grid starting at location 20, * then going down, then left, then up twice. * * @param grid An array of integers between 0 and 9, where the size of the * array is square (1, 4, 9, 16 etc). * @param target A target number which may be hidden in the grid. * @return If the target number is hidden in the grid, return the location * (index) within the grid of the first digit of the target number, or -1 * if it is not in the grid. */ public static int find(int[] grid, int target) { return -2; // FIXME complete this method } }