【leetcode】1409. Queries on a Permutation With Key
题目如下:
Given the array
queries
of positive integers between1
andm
, you have to process allqueries[i]
(fromi=0
toi=queries.length-1
) according to the following rules:
- In the beginning, you have the permutation
P=[1,2,3,...,m]
.- For the current
i
, find the position ofqueries[i]
in the permutationP
(indexing from 0) and then move this at the beginning of the permutationP.
Notice that the position ofqueries[i]
inP
is the result forqueries[i]
.Return an array containing the result for the given
queries
.Example 1:
Input: queries = [3,1,2,1], m = 5 Output: [2,1,2,1] Explanation: The queries are processed as follow: For i=0: queries[i]=3, P=[1,2,3,4,5], position of 3 in P is 2, then we move 3 to the beginning of P resulting in P=[3,1,2,4,5]. For i=1: queries[i]=1, P=[3,1,2,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,3,2,4,5]. For i=2: queries[i]=2, P=[1,3,2,4,5], position of 2 in P is 2, then we move 2 to the beginning of P resulting in P=[2,1,3,4,5]. For i=3: queries[i]=1, P=[2,1,3,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,2,3,4,5]. Therefore, the array containing the result is [2,1,2,1].Example 2:
Input: queries = [4,1,2,2], m = 4 Output: [3,1,2,0]Example 3:
Input: queries = [7,5,5,8,3], m = 8 Output: [6,5,0,7,5]Constraints:
1 <= m <= 10^3
1 <= queries.length <= m
1 <= queries[i] <= m
解题思路:很简单的题目,按题目要求来就行了。
代码如下:
class Solution(object): def processQueries(self, queries, m): """ :type queries: List[int] :type m: int :rtype: List[int] """ q = range(1,m+1) res = [] for v in queries: inx = q.index(v) res.append(inx) del q[inx] q = [v] + q return res