308365: CF1508B. Almost Sorted
Memory Limit:256 MB
Time Limit:2 S
Judge Style:Text Compare
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Description
Almost Sorted
题意翻译
如果一个长度为 $n$ 的排列 $a$ 满足对于任意整数 $i\in[1,n-1]$ 都有 $a_{i+1}\geq a_i-1$,我们就说这个排列是“几乎有序的”。 给定 $n,k$,求所有长度为 $n$ 的“几乎有序的”排列中,字典序第 $k$ 小的那个。特别的,如果这样的排列不存在,输出 $-1$。$T$ 组数据。 $1\leq T\leq10^3;1\leq n,\sum n\leq10^5;1\leq k\leq10^{18};$题目描述
Seiji Maki doesn't only like to observe relationships being unfolded, he also likes to observe sequences of numbers, especially permutations. Today, he has his eyes on almost sorted permutations. A permutation $ a_1, a_2, \dots, a_n $ of $ 1, 2, \dots, n $ is said to be almost sorted if the condition $ a_{i + 1} \ge a_i - 1 $ holds for all $ i $ between $ 1 $ and $ n - 1 $ inclusive. Maki is considering the list of all almost sorted permutations of $ 1, 2, \dots, n $ , given in lexicographical order, and he wants to find the $ k $ -th permutation in this list. Can you help him to find such permutation? Permutation $ p $ is lexicographically smaller than a permutation $ q $ if and only if the following holds: - in the first position where $ p $ and $ q $ differ, the permutation $ p $ has a smaller element than the corresponding element in $ q $ .输入输出格式
输入格式
The first line contains a single integer $ t $ ( $ 1\le t\le 1000 $ ) — the number of test cases. Each test case consists of a single line containing two integers $ n $ and $ k $ ( $ 1 \le n \le 10^5 $ , $ 1 \le k \le 10^{18} $ ). It is guaranteed that the sum of $ n $ over all test cases does not exceed $ 10^5 $ .
输出格式
For each test case, print a single line containing the $ k $ -th almost sorted permutation of length $ n $ in lexicographical order, or $ -1 $ if it doesn't exist.
输入输出样例
输入样例 #1
5
1 1
1 2
3 3
6 5
3 4
输出样例 #1
1
-1
2 1 3
1 2 4 3 5 6
3 2 1