Stack Data Structure (Introduction and Program)

Stack is a linear data structure which follows a particular order in which the operations are performed. The order may be LIFO(Last In First Out) or FILO(First In Las...

Root to leaf path sum equal to a given number

Given a binary tree and a number, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals the given number. Return fa...

Dijkstra’s shortest path algorithm Greedy Algo-7

Given a graph and a source vertex in the graph, find shortest paths from source to all vertices in the given graph. Dijkstra’s algorithm is very similar to Pr...

Write a program to print all permutations of a given string

A permutation, also called an “arrangement number” or “order,” is a rearrangement of the elements of an ordered list S into a one-to-one c...

HeapSort

Heap sort is a comparison based sorting technique based on Binary Heap data structure. It is similar to selection sort where we first find the maximum element and pl...

Count number of bits to be flipped to convert A to B

Given two numbers ‘a’ and b’. Write a program to count number of bits needed to be flipped to convert ‘a’ to ‘b’. Ex...

Swap two nibbles in a byte

A nibble is a four-bit aggregation, or half an octet. There are two nibbles in a byte. Given a byte, swap the two nibbles in it. For example 100 is be represented as ...

Minimum Initial Points to Reach Destination

Given a grid with each cell consisting of positive, negative or no points i.e, zero points. We can move across a cell only if we have positive points ( > 0 ). When...

Dijkstra’s shortest path algorithm Greedy Algo-7

Given a graph and a source vertex in the graph, find shortest paths from source to all vertices in the given graph. Dijkstra’s algorithm is very similar to Pr...

Count ways to reach the n’th stair

There are n stairs, a person standing at the bottom wants to reach the top. The person can climb either 1 stair or 2 stairs at a time. Count the number of ways, the p...