Shortest path of the king

                                                                                                                A. Shortest path of the king

                                                                                                                      time limit per test

                                                                                                                            1 second

                                                                                                                   memory limit per test

                                                                                                                        64 megabytes

                                                                                                                               input

                                                                                                                        standard input

                                                                                                                              output

                                                                                                                        standard output

The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he has to pay an official visit to squaret. As the king is not in habit of wasting his time, he wants to get from his current positions to square t in the least number of moves. Help him to do this.

In one move the king can get to the square that has a common side or a common vertex with the square the king is currently in (generally there are 8 different squares he can move to).

Input

The first line contains the chessboard coordinates of square s, the second line — of square t.

Chessboard coordinates consist of two characters, the first one is a lowercase Latin letter (froma to h), the second one is a digit from1 to 8.

Output

In the first line print n — minimum number of the king's moves. Then inn lines print the moves themselves. Each move is described with one of the 8:L, R,U, D,LU, LD,RU or RD.

L, R,U, D stand respectively for moves left, right, up and down (according to the picture), and 2-letter combinations stand for diagonal moves. If the answer is not unique, print any of them.

Sample test(s)

Input

a8h1

Output

7RDRDRDRDRDRDRD

  本题的第一个输出的是步数，取决于字母之间的差值以及数值之间的差的最大值，之后在输出方向即可，水题。（大一学生，代码不会有很多不足）

  (原题链接）http://codeforces.com/problemset/problem/3/A         

#include <iostream>#include <cstring>#include <cstdio>using namespace std;int main(){   char a,b;    int num1,num2;    while(scanf("%c%d",&b,&num2)!=-1){      getchar();      scanf("%c%d",&a,&num1);      getchar();       int min1=0,min2=0,min3=0,min4=0;       min3=min1=(a-b);       int max=0;        if(min1<0) {min3=-1*min1;}  //由于输出须取正值，所以要判断差值的正负       min4=min2=(num1-num2);       if(min2<0) {min4=-1*min2;}   //同上      if(min3>=min4) max=min3;       else max=min4;       cout<<max<<endl;       for(int i=0;i<max;i++){             if(min1>0) {if(min2==0) {cout<<"R"<<endl;  min1--;} else {cout<<"R";  min1--;}}             if(min1<0) {if(min2==0) {cout<<"L"<<endl;  min1++;} else {cout<<"L";  min1++;}}             if(min2>0) {cout<<"U"<<endl;  min2--;}             if(min2<0) {cout<<"D"<<endl;  min2++;}       }    }    return 0;}