CF1935C.Messenger in MAC

传统题 时间 2000 ms 内存 256 MiB 9 尝试 3 已通过 1 标签

Messenger in MAC

In the new messenger for the students of the Master's Assistance Center, Keftemerum, an update is planned, in which developers want to optimize the set of messages shown to the user. There are a total of nn messages. Each message is characterized by two integers aia_i and bib_i. The time spent reading the set of messages with numbers p1,p2,,pkp_1, p_2, \ldots, p_k (1pin1 \le p_i \le n, all pip_i are distinct) is calculated by the formula:

$$\Large \sum_{i=1}^{k} a_{p_i} + \sum_{i=1}^{k - 1} |b_{p_i} - b_{p_{i+1}}|$$</p><p>Note that the time to read a set of messages consisting of <span class="tex-font-style-bf">one</span> message with number$p\_1$is equal to$a\_{p\_1}$. Also, the time to read an empty set of messages is considered to be$0$.</p><p>The user can determine the time$l$that he is willing to spend in the messenger. The messenger must inform the user of the maximum possible size of the set of messages, the reading time of which does not exceed$l$. Note that the maximum size of the set of messages can be equal to$0$. The developers of the popular messenger failed to implement this function, so they asked you to solve this problem. ## Input Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \leq t \leq 5 \cdot 10^4$) — the number of test cases. The description of the test cases follows. The first line of each test case contains two integers $n$ and $l$ ($1 \leq n \leq 2000$, $1 \leq l \leq 10^9$) — the number of messages and the time the user is willing to spend in the messenger. The $i$-th of the next $n$ lines contains two integers $a_i$ and $b_i$ ($1 \le a_i, b_i \le 10^9$) — characteristics of the $i$-th message. It is guaranteed that the sum of $n^2$ over all test cases does not exceed $4 \cdot 10^6$. ## Output For each test case, output a single integer — the maximum possible size of a set of messages, the reading time of which does not exceed $l$. ## Note In the first test case, you can take a set of three messages with numbers $p_1 = 3$, $p_2 = 2$, and $p_3 = 5$. The time spent reading this set is equal to $a_3 + a_2 + a_5 + |b_3 - b_2| + |b_2 - b_5| = 2 + 1 + 2 + |4 - 5| + |5 - 3| = 8$. In the second test case, you can take a set of one message with number $p_1 = 1$. The time spent reading this set is equal to $a_1 = 4$. In the fifth test case, it can be shown that there is no such non-empty set of messages, the reading time of which does not exceed $l$. ## Samples ```input1 5 5 8 4 3 1 5 2 4 4 3 2 3 1 6 4 10 3 12 4 8 2 1 2 12 5 26 24 7 8 28 30 22 3 8 17 17 5 14 15 3 1000000000 998244353 179 239 228 1337 993 1007 ``` ```output1 3 1 2 1 0 ```$$

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