POJ 1166 The Clocks (Mob search)

The Clocks

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 15944		Accepted: 6493

Description

|-------|    | -------|    | -------|
|       |    |       |    |   |   |
|---O   |    | ---O   |    |   O   |
|       |    |       |    |       |
|-------|    | -------|    | -------|
    A            B            C    

|-------|    | -------|    | -------|
|       |    |       |    |       |
|   O   |    |   O   |    |   O   |
|   |   |    |   |   |    |   |   |
|-------|    | -------|    | -------|
    D            E            F    

|-------|    | -------|    | -------|
|       |    |       |    |       |
|   O   |    |   O---|    |   O   |
|   |   |    |       |    |   |   |
|-------|    | -------|    | -------|
    G            H            I    
(Figure 1)

There is nine clocks in a 3*3 array (Figure 1). The goal is to return all of the dials to O ' clock with as few moves as possible. There is nine different allowed ways to turn the dials on the clocks. Each such-by is called a move. Select for each move a number 1 to 9. That number would turn the dials "(degrees) clockwise on those clocks which is affected according to Figure 2 below.

Move   Affected Clocks

1         Abde
2         ABC
3         BCEF
4         ADG
5         Bdefh
6         CFI
7         Degh
8         GHI
9         Efhi    
   (Figure 2)

Input

Your program was to read from standard input. Nine numbers give the start positions of the dials. 0=12 o ' clock, 1=3 o ' clock, 2=6 o ' clock, 3=9 o ' clock.

Output

Your program is-to-write to standard output. Output a shortest sorted sequence of moves (numbers), which returns all the dials to O ' clock. Convinced that's the answer is unique.

Sample Input

3 3 02 2 22 1 2

Sample Output

4 5 8 9

Analysis: began to figure out BFS, but also a very large array of record path, written half a day did not write it out. So look at other people's blogs, copy the following methods. The main is what kind of move first, then what kind of movement, the results have no effect, so you can search in a fixed order.

Java AC Code

ImportJava.util.Scanner; Public classtheclocks_1166 { Public Static voidMain (string[] args) {Scanner sc=NewScanner (system.in); intA[] =New int[10];//array A is the input data         for(inti = 1; I <= 9; i++) {A[i]=Sc.nextint (); }        intB[] =New int[10]; intC[] =New int[10];  for(b[1]=0;b[1]<=3;b[1]++)//Array B is used to store 9 ways of moving, each of which can be used 0~3 times, then brute-force search continues         for(b[2]=0;b[2]<=3;b[2]++)//a total of 4 of 9 species may         for(b[3]=0;b[3]<=3;b[3]++)//because the AAB movement and the ABA movement result in the same results, so the order can be fixed         for(b[4]=0;b[4]<=3;b[4]++)         for(b[5]=0;b[5]<=3;b[5]++)         for(b[6]=0;b[6]<=3;b[6]++)         for(b[7]=0;b[7]<=3;b[7]++)         for(b[8]=0;b[8]<=3;b[8]++)         for(b[9]=0;b[9]<=3;b[9]++) {c[1]= (a[1]+b[1]+b[2]+b[4])%4;//The array C indicates the state of the clock after the move.C[2]= (a[2]+b[1]+b[2]+b[3]+b[5])%4;//and the effect of a movement on a clock.C[3]= (A[3]+b[2]+b[3]+b[6])%4; c[4]= (A[4]+b[1]+b[4]+b[5]+b[7])%4; c[5]= (a[5]+b[1]+b[3]+b[5]+b[7]+b[9])%4; c[6]= (a[6]+b[3]+b[5]+b[6]+b[9])%4; c[7]= (A[7]+b[4]+b[7]+b[8])%4; c[8]= (a[8]+b[5]+b[7]+b[8]+b[9])%4; c[9]= (a[9]+b[6]+b[8]+b[9])%4; if(c[1]+c[2]+c[3]+c[4]+c[5]+c[6]+c[7]+c[8]+c[9]==0)//when it's all 0, the output           {              for(inti=0;i<b[1];i++) System.out.print ("1");  for(inti=0;i<b[2];i++) System.out.print ("2");  for(inti=0;i<b[3];i++) System.out.print ("3");  for(inti=0;i<b[4];i++) System.out.print ("4");  for(inti=0;i<b[5];i++) System.out.print ("5");  for(inti=0;i<b[6];i++) System.out.print ("6");  for(inti=0;i<b[7];i++) System.out.print ("7");  for(inti=0;i<b[8];i++) System.out.print ("8");  for(inti=0;i<b[9];i++) System.out.print ("9"); System.out.print ("\ n"); return; }        }        }}

POJ 1166 The Clocks (Mob search)