HDOJ1195 Open the Lock

题意：

给俩个四位数，第一个变到到第二个最少需要多少步

每一个只能 每一位+-1（一次操作一个数 不能同时操作不同位）

1-1=0则变9 9+1=10则变1

或者相邻俩位数字交换 第一位和第四位不算相邻位

解题思路：

将四位数转换成四位数组，每一个四位数对应一个位置，这样可以用广搜寻找俩个位置之间的最短路径

广搜原理点此

import java.util.LinkedList;
import java.util.Scanner;

public class Main{

static Number[][][][] numbers=new Number[10][10][10][10];
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
for (int i = 1; i < numbers.length; i++) {
for (int j = 1; j < numbers[i].length; j++) {
for (int j2 = 1; j2 < numbers[i][j].length; j2++) {
for (int k = 1; k < numbers[i][j][j2].length; k++) {
numbers[i][j][j2][k]=new Number(i, j, j2, k);
}
}
}
}
while(sc.hasNext()){
int n=sc.nextInt();
while(n-->0){
for (int i = 1; i < numbers.length; i++) {
for (int j = 1; j < numbers[i].length; j++) {
for (int j2 = 1; j2 < numbers[i][j].length; j2++) {
for (int k = 1; k < numbers[i][j][j2].length; k++) {
numbers[i][j][j2][k].isVisit=false;
numbers[i][j][j2][k].time=0;
}
}
}
}
String s1=sc.next();
String s2=sc.next();
Number first=numbers[s1.charAt(0)-'0'][s1.charAt(1)-'0'][s1.charAt(2)-'0'][s1.charAt(3)-'0'];
first.isVisit=true;
NumberQueue queue=new NumberQueue();
queue.push(first);
searchNumberBFS(queue,numbers[s2.charAt(0)-'0'][s2.charAt(1)-'0'][s2.charAt(2)-'0'][s2.charAt(3)-'0']);
}
}
}
static int dir[][]={{1,0,0,0},{-1,0,0,0},
{0,1,0,0},{0,-1,0,0},
{0,0,1,0},{0,0,-1,0},
{0,0,0,1},{0,0,0,-1}};
private static void searchNumberBFS(NumberQueue queue,Number number) {
while(!queue.isEmpty()){
Number num=queue.pop();
for (int i = 0; i < dir.length; i++) {
int a=num.a+dir[i][0];
a=change(a);
int b=num.b+dir[i][1];
b=change(b);
int c=num.c+dir[i][2];
c=change(c);
int d=num.d+dir[i][3];
d=change(d);
if(ajust(queue, number, num, a, b, c, d))
return;
}
int a=num.a;
int b=num.b;
int c=num.c;
int d=num.d;
if(ajust(queue, number, num, b, a, c, d))
return;
if(ajust(queue, number, num, a, c, b, d))
return;
if(ajust(queue, number, num, a, b, d, c))
return;

}
}
private static boolean ajust(NumberQueue queue, Number number, Number num,
int a, int b, int c, int d) {
if(!numbers[a][b][c][d].isVisit){
numbers[a][b][c][d].time=num.time+1;
if(a==number.a&&b==number.b&&c==number.c&&d==number.d){
System.out.println(number.time);
return true;
}
numbers[a][b][c][d].isVisit=true;
queue.push(numbers[a][b][c][d]);
}
return false;
}
private static int change(int a) {
a=(a==10?1:a);
a=(a==0?9:a);
return a;
}
static class Number{
int a,b,c,d;
int time;
boolean isVisit;
public Number(int a, int b, int c, int d) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
}
}
static class NumberQueue{
LinkedList<Number> lkl=new LinkedList<Number>();
public void push(Number b){
lkl.add(b);
}
public Number pop(){
return lkl.pollFirst();
}
public boolean isEmpty(){
return lkl.isEmpty();
}
}
}