Convert max heap to min heap in linear time
Given an array representing a max-heap, in-place convert it into the min-heap in linear time.
Tag: Easy
Determine whether a string is a palindrome or not
Write a program to determine if a given string is palindrome or not. A palindromic string is a string that remains the same with its characters reversed.
Activity Selection Problem
Given a set of activities, along with the starting and finishing time of each activity, find the maximum number of activities performed by a single person assuming that a person can only work on a single activity at a time.
All-Pairs Shortest Paths – Floyd Warshall Algorithm
Given a set of vertices V in a weighted graph where its edge weights w(u, v) can be negative, find the shortest path weights d(s, v) from every source s for all vertices v present in the graph. If the graph contains a negative-weight cycle, report it.
Check if a graph is strongly connected or not
Given a directed graph, check if it is strongly connected or not. A directed graph is said to be strongly connected if every vertex is reachable from every other vertex.
Transitive closure of a graph
The transitive closure for a digraph G is a digraph G’ with an edge (i, j) corresponding to each directed path from i to j in G. The resultant digraph G’ representation in the form of the adjacency matrix is called the connectivity matrix.
Arrival and departure time of vertices in DFS
The arrival time is the time at which the vertex was explored for the first time in the DFS, and departure time is the time at which we have explored all the neighbors of the vertex, and we are ready to backtrack.
Reverse a string using recursion – C, C++, and Java
Write a recursive program to efficiently reverse a given string in C, C++, and Java.
Iterative solution to reverse a string in C++ and Java
Write an iterative program to reverse a string in C++ and Java.
Recursive program to calculate factorial of a number
Write a recursive C/C++, Java, and Python program to calculate the factorial of a given positive number.
Find all factorial numbers less than or equal to n
Write a recursive program to find all factorial numbers less than or equal to n. The factorial n! of a non-negative integer n is the product of all positive integers less than or equal to n.
Iterative program to find factorial of a number
Write an iterative C/C++ and java program to find factorial of a given positive number.