Given an array of distinct integers
nums and a target integer
target, return the number of possible combinations that add up to
The answer is guaranteed to fit in a 32-bit integer.
matrix and a
target, return the number of non-empty submatrices that sum to target.
x1, y1, x2, y2 is the set of all cells
matrix [x][y] with
x1 <= x <= x2 and
y1 <= y <= y2.
(x1, y1, x2, y2) and
(x1', y1', x2', y2') are different if they have some coordinate that is different: for example, if
x1 != x1'.
You are given a string
s and an integer
k duplicate removal consists of choosing
k adjacent and equal letters from
s and removing them, causing the left and the right side of the deleted substring to concatenate together.
We repeatedly make
k duplicate removals on
s until we no longer can.
Return the final string after all such duplicate removals have been made. It is guaranteed that the answer is unique.
You are given a nested list of integers
nestedList. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it.
NestedIterator (List<NestedInteger> nestedList)Initializes the iterator with the nested list
int next ()Returns the next integer in the nested list.
boolean hasNext ()Returns
trueif there are still some integers in the nested list and
Given two integers
k, construct a list
answer that contains
n different positive integers ranging from
n and obeys the following requirement:
answer = [a1, a2, a3, ... , an], then the list
[|a1 - a2|, |a2 - a3|, |a3 - a4|, ... , |an-1 - an|]has exactly
Return the list
answer. If there multiple valid answers, return any of them.