Given an integer n
, return true
if it is a power of two. Otherwise, return false
.
An integer n
is a power of two, if there exists an integer x
such that n == 2x
.
Example 1:
Input: n = 1
Output: true
Explanation: 20 = 1
Example 2:
Input: n = 16
Output: true
Explanation: 24 = 16
Example 3:
Input: n = 3
Output: false
Constraints:
-231 <= n <= 231 - 1
Solution
Time Complexity O(log n)
Space Complexity O(log n)
Time Complexity O(log n)
Space Complexity O(1)
Given the head
of a linked list and an integer val
, remove all the nodes of the linked list that has Node.val == val
, and return the new head.
Example 1:
Input: head = [1,2,6,3,4,5,6], val = 6
Output: [1,2,3,4,5]
Example 2:
Input: head = [], val = 1
Output: []
Example 3:
Input: head = [7,7,7,7], val = 7
Output: []
Constraints:
- The number of nodes in the list is in the range
[0, 104]
. 1 <= Node.val <= 50
0 <= val <= 50
Solution
Time Complexity O(n)
Space Complexity O(n)
Time Complexity O(n)
Space Complexity O(n)
Do you see that green follow button? π
Implement pow(x, n), which calculates x
raised to the power n
(i.e., xn
).
Example 1:
Input: x = 2.00000, n = 10
Output: 1024.00000
Example 2:
Input: x = 2.10000, n = 3
Output: 9.26100
Example 3:
Input: x = 2.00000, n = -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25
Constraints:
-100.0 < x < 100.0
-231 <= n <= 231-1
-104 <= xn <= 104
Solution
Time Complexity O(n)
Space Complexity O(1)
Time Complexity O(log n)
Space Complexity O(log n)
Time Complexity O(log n)
Space Complexity O(1)
Given an m x n
integer matrix matrix
, if an element is 0
, set its entire row and column to 0
's.
You must do it in place.
Example 1:
Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
Output: [[1,0,1],[0,0,0],[1,0,1]]
Example 2:
Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]]
such that i != j
, i != k
, and j != k
, and nums[i] + nums[j] + nums[k] == 0
.
Notice that the solution set must not contain duplicate triplets.
Example 1:
Input: nums = [-1,0,1,2,-1,-4]
Output: [[-1,-1,2],[-1,0,1]]
Example 2:
Input: nums = []
Output: []
Example 3:
Input: nums = [0]
Output: []
Constraints:
0 <= nums.length <= 3000
-105 <= nums[i] <= 105
Solution
Time Complexity O(nΒ³)
Space Complexity O(d) where d is the number of possible sets
Time Complexity O(nΒ²)
Space Complexity O(n + d) where d is the number of possible sets