Today is an example of The non-Designer's Design Book on bottom of Page 134 and Queries on a Permutation With Key on leetcode and leetcode's October LeetCoding Challenge with cpp.

The non-Designer's Design Book

my answer:

• first one:
  • [F] neat left alignment
  • [F] use divide line insead of ·
  • [T] renove useless shape
  • [HT] increase font size of company name
  • [T] not using italic font on title
  • [F] unify font
• second one:
  • [T] add black banner for the title and contact information
  • [F] uing .. instead of ·
  • [T] leave no space on left of image
  • [T] not uing italic font on title

Queries on a Permutation With Key

Description

Given a linked list, rotate the list to the right by k places, where k is non-negative.

Example 1:

Input: 1->2->3->4->5->NULL, k = 2
Output: 4->5->1->2->3->NULL
Explanation:
rotate 1 steps to the right: 5->1->2->3->4->NULL
rotate 2 steps to the right: 4->5->1->2->3->NULL

Example 2:

Input: 0->1->2->NULL, k = 4
Output: 2->0->1->NULL
Explanation:
rotate 1 steps to the right: 2->0->1->NULL
rotate 2 steps to the right: 1->2->0->NULL
rotate 3 steps to the right: 0->1->2->NULL
rotate 4 steps to the right: 2->0->1->NULL

Given the array queries of positive integers between 1 and m, you have to process all queries[i] (from i=0 to i=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 of queries[i] in the permutation P (indexing from 0) and then move this at the beginning of the permutation P. Notice that the position of queries[i] in P is the result for queries[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

Solution

using std::list with brute force

BIT seems can solve it, leave it for review days.

class Solution {
public:
  vector<int> processQueries(vector<int>& queries, int m) {
    list<int> permutation;
    vector<int> ans;
    for(int i = 0; i < m; ++i) {
      permutation.push_back(i+1);
    }
    for(int i = 0; i < queries.size(); ++i) {
      auto it = find(permutation.begin(), permutation.end(), queries[i]);
      ans.push_back(distance(permutation.begin(), it));
      permutation.erase(it);
      permutation.push_front(queries[i]);
    }
    return ans;
  }
};

October LeetCoding Challenge 8

Description

Binary Search

Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, then return its index, otherwise return -1. Example 1:

Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4

Example 2:

Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1

Note:

1. You may assume that all elements in nums are unique.
2. n will be in the range [1, 10000].
3. The value of each element in nums will be in the range [-9999, 9999].

Solution

naive problem, using stl solve it.

class Solution {
public:
    int search(vector<int>& nums, int target) {
        auto it = lower_bound(nums.begin(), nums.end(), target);
        if (*it != target) return -1;
        return distance(nums.begin(), it);
    }
};