首页 > 代码库 > Snake and Ladder Problem
Snake and Ladder Problem
Given a snake and ladder board, find the minimum number of dice throws required to reach the destination or last cell from source or 1st cell. Basically, the player has total control over outcome of dice throw and wants to find out minimum number of throws required to reach last cell.
If the player reaches a cell which is base of a ladder, the player has to climb up that ladder and if reaches a cell is mouth of the snake, has to go down to the tail of snake without a dice throw.
O(n) BFS
/** * Given a snake and ladder board, find the minimum number of dice throws required to reach the destination or last cell from source or 1st cell. Basically, the player has total control over outcome of dice throw and wants to find out minimum number of throws required to reach last cell. * If the player reaches a cell which is base of a ladder, the player has to climb up that ladder and if reaches a cell is mouth of the snake, has to go down to the tail of snake without a dice throw. * @author */ import java.util.*; class Grid{ int index; int distance; public Grid(int index, int distance){ this.index = index; this.distance = distance; } } public class SnakeAndLadderProblem { public static int miniStep(int[] board){ int min = 0; boolean visited[] = new boolean[board.length]; Queue<Grid> queue = new LinkedList<Grid>(); Grid root = new Grid(0,0); visited[0] = true; queue.offer(root); while(!queue.isEmpty()){ Grid top = queue.poll(); if(top.index == board.length -1){ min = top.distance; break; } for(int i = top.index + 1; i <= top.index + 6 && i < board.length; i++){ if(visited[i] == false){ Grid newGrid = null; visited[i] = true; if(board[i] !=-1) newGrid = new Grid(board[i], top.distance + 1); else newGrid = new Grid(i, top.distance + 1); queue.add(newGrid); } } } return min; } public static void main(String[] args) { // TODO Auto-generated method stub int board[] = new int[30]; for(int i = 0; i < 30; i++){ board[i] = -1; } // Ladders board[2] = 21; board[4] = 7; board[10] = 25; board[19] = 28; // Snakes board[26] = 0; board[20] = 8; board[16] = 3; board[18] = 6; System.out.println("min step is "+ miniStep(board)); } }
Snake and Ladder Problem
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。