Find minimum path sum in a triangle-shaped matrix
Given a right-angled triangle-shaped matrix, find the shortest path sum from the top element to any element in the last row of the matrix.
Tag: Medium
Find all increasing subsequences of an array
Given an integer array, find all distinct increasing subsequences of length two or more.
Find kth smallest value in a sorted matrix
Given a row-wise and column-wise sorted square matrix and a positive integer k, find the kth smallest number in the matrix.
Find start node of the cycle in a linked list
Given a linked list containing a cycle, return the starting node of the cycle without modifying the list. Report if there are no cycles in the linked list.
Insert an interval by merging overlapping intervals
Insert the specified interval into a collection of non-overlapping intervals that has been organized by the start time of each interval. If the new interval causes intervals to overlap, merge the overlapped intervals.
Construct smallest number after removing k digits from a string
Given the string representation of a non-negative integer and an integer k, find the smallest number that remains after taking out k digits from it.
Count distinct permutations of an array that sums to a target
Given an array of distinct positive integers, find the total number of distinct permutations that add up to a given target, where each array element may be used any number of times.
Count quadruplets with a zero sum
Given four integer arrays, count the number of quadruplets with a zero sum, including exactly one element from each array.
Calculate sum of root to leaf digits in a binary tree
Given a binary tree, where each node stores a value between 0 and 9, calculate the sum of the numbers created by the paths from root to leaf.
Find all distinct combinations of a given length that sum to a target
Given a positive integer n and a target, find all combinations of distinct numbers in the interval [1,9] of length n that add up to the target.
Longest Alternating Subsequence Problem – II
Given an integer array, find the length of the longest subsequence with alternate low and high elements in the array.
Check whether a directed graph is Eulerian
An Eulerian trail (or Eulerian path) is a path in a graph that visits every edge exactly once. Given a directed graph, check whether it has an Eulerian path or not.