CF1481A.Space Navigation

You were dreaming that you are traveling to a planet named Planetforces on your personal spaceship. Unfortunately, its piloting system was corrupted and now you need to fix it in order to reach Planetforces.

Space can be represented as the $XY$ plane. You are starting at point $(0, 0)$, and Planetforces is located in point $(p_x, p_y)$.

The piloting system of your spaceship follows its list of orders which can be represented as a string $s$. The system reads $s$ from left to right. Suppose you are at point $(x, y)$ and current order is $s_i$:

• if $s_i = \text{U}$, you move to $(x, y + 1)$;
• if $s_i = \text{D}$, you move to $(x, y - 1)$;
• if $s_i = \text{R}$, you move to $(x + 1, y)$;
• if $s_i = \text{L}$, you move to $(x - 1, y)$.

Since string $s$ could be corrupted, there is a possibility that you won't reach Planetforces in the end. Fortunately, you can delete some orders from $s$ but you can't change their positions.

Can you delete several orders (possibly, zero) from $s$ in such a way, that you'll reach Planetforces after the system processes all orders?

你梦见自己正乘坐私人宇宙飞船前往一颗名为 Planetforces 的星球。不幸的是，飞船的导航系统遭到损坏，现在你必须修复它，才能抵达 Planetforces。

太空可被建模为 $XY$ 平面。你从点 $(0, 0)$ 出发，而 Planetforces 位于点 $(p_x, p_y)$。

飞船导航系统依据其指令列表运行，该列表可用一个字符串 $s$ 表示。系统从左到右依次读取 $s$ 中的字符。假设当前你位于点 $(x, y)$，且当前指令为 $s_i$：

• 若 $s_i = \text{U}$，则移动至 $(x, y + 1)$；
• 若 $s_i = \text{D}$，则移动至 $(x, y - 1)$；
• 若 $s_i = \text{R}$，则移动至 $(x + 1, y)$；
• 若 $s_i = \text{L}$，则移动至 $(x - 1, y)$。

由于字符串 $s$ 可能已损坏，你最终可能无法抵达 Planetforces。幸运的是，你可以从 $s$ 中删除若干指令（但不能改变剩余指令的相对顺序）。

你能否通过删除若干指令（也可以不删），使得系统执行完所有剩余指令后，恰好抵达 Planetforces？

The first line contains a single integer $t$ ($1 \le t \le 1000$) — the number of test cases.

Each test case consists of two lines. The first line in each test case contains two integers $p_x$ and $p_y$ ($-10^5 \le p_x, p_y \le 10^5$; $(p_x, p_y) \neq (0, 0)$) — the coordinates of Planetforces $(p_x, p_y)$.

The second line contains the string $s$ ($1 \le |s| \le 10^5$: $|s|$ is the length of string $s$) — the list of orders.

It is guaranteed that the sum of $|s|$ over all test cases does not exceed $10^5$.

第一行包含一个整数 $t$（$1 \le t \le 1000$）—— 测试用例的数量。

每个测试用例由两行组成。每个测试用例的第一行包含两个整数 $p_x$ 和 $p_y$（$-10^5 \le p_x, p_y \le 10^5$；且 $(p_x, p_y) \neq (0, 0)$）—— 行星力（Planetforces）的坐标 $(p_x, p_y)$。

第二行包含一个字符串 $s$（$1 \le |s| \le 10^5$，其中 $|s|$ 表示字符串 $s$ 的长度）—— 指令列表。

保证所有测试用例中 $|s|$ 的总和不超过 $10^5$。

For each test case, print "YES" if you can delete several orders (possibly, zero) from $s$ in such a way, that you'll reach Planetforces. Otherwise, print "NO". You can print each letter in any case (upper or lower).

对于每个测试用例，如果可以通过删除字符串 $s$ 中的若干个订单（可能为零个），从而到达 Planetforces，则输出 "YES"；否则输出 "NO"。你可以以任意大小写形式输出每个字母（大写或小写）。

In the first case, you don't need to modify $s$, since the given $s$ will bring you to Planetforces.

In the second case, you can delete orders $s_2$, $s_3$, $s_4$, $s_6$, $s_7$ and $s_8$, so $s$ becomes equal to "UR".

In the third test case, you have to delete order $s_9$, otherwise, you won't finish in the position of Planetforces.

在第一种情况下，您无需修改 $s$，因为给定的 $s$ 已能将您带到 Planetforces。

在第二种情况下，您可以删除指令 $s_2$、$s_3$、$s_4$、$s_6$、$s_7$ 和 $s_8$，从而使 $s$ 变为 "UR"。

在第三个测试用例中，您必须删除指令 $s_9$，否则您将无法最终停留在 Planetforces 的位置。