题目描述
Problem Statement
Consider an infinite two-dimensional coordinate plane.
Takahashi, who is initially standing at (0,0), will do N jumps in one of the four directions he chooses every time: up, down, left, or right.
The length of each jump is fixed. Specifically, the i-th jump should cover the distance of D_i.
Determine whether it is possible to be exactly at (A, B) after N jumps. If it is possible, show one way to do so.
Here, for each direction, a jump of length D from (X, Y) takes him to the following point:
- up: $(X,Y) \to$ (X,Y+D)
- down: $(X,Y) \to$ (X,Y-D)
- left: $(X,Y) \to$ (X-D,Y)
- right: $(X,Y) \to$ (X+D,Y).
Input
Input is given from Standard Input in the following format:
N A B
$D_1 D_2 \ldots D_N$
Output
In the first line, print Yes if there is a desired sequence of jumps, and No otherwise.
In the case of Yes, print in the second line a desired sequence of jumps as a string S of length N consisting of U , D , L , R, as follows:
- if the i-th jump is upward, the i-th character should be U;
- if the i-th jump is downward, the i-th character should be D;
- if the i-th jump is to the left, the i-th character should be L;
- if the i-th jump is to the right, the i-th character should be R.
Constraints
- $1 \leq N \leq 2000$
- $\lvert A\rvert, \lvert B\rvert \leq 3.6\times 10^6$
- $1 \leq D_i \leq 1800$
- All values in input are integers.
Sample Input 1
3 2 -2
1 2 3
Sample Output 1
Yes
LDR
If he jumps left, down, right in this order, Takahashi moves $(0,0)\to(-1,0)\to(-1,-2)\to(2,-2)$ and ends up at (2, -2), which is desired.
Sample Input 2
2 1 0
1 6
Sample Output 2
No
It is impossible to be exactly at (1, 0) after the two jumps.
Sample Input 3
5 6 7
1 3 5 7 9
Sample Output 3
Yes
LRLUR
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分