Objective: Given an Infix expression, write an algorithm to convert it into Postfix expression. Example: Input: Infix expression – A + B Output: Postfix expression- AB+ Input: Infix expression – A+B*(C^D-E) Output: Postfix expression-...
Infix notation is commonly used in arithmetic formula or statements, the operators are written in-between their operands. Let’s assume the below Operands are real numbers. Permitted operators: +,-, *, /, ^(exponentiation) Blanks are permitted...
Objective: Given a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[‘ and ‘]’, determine if the input string is valid. Example: ()()([]({}))[] valid: true ()({]) valid: false []{}() valid: true [(}{)] valid: false Earlier we had seen problem Valid...
Objective: Given two numbers, n and k (k>=n), write an algorithm to generate all the strings of length n drawn from 0 – k-1. Example: k = 2, n = 2Output: 0 0 0...
Objective: Given an array of integers A[],find no of reverse pairs means no of (i, j) pairs where i < j and A[i]>A[j]. Example: A[] = {10, 3, 4, 2, 5, 7, 9, 11}...
What is Heap Sort?? Heap sort is comparison based sorting algorithm. Heap sort is considered as improved selection sort, it divides the input into sorted and unsorted region. The improvement from selection sort is...
Objective – Given a number, Write a program to get the sum of digits in a number till it become a single digit. Example: N = 999 -> 9+9+9 = 27-> 2+7 = 9...
Objective: Given a number, write a program to check if the number is prime or not. Prime Number: A number is called a prime number when number is not divisible by 1 or by...
Objective– Given two numbers, swap both the numbers using XOR operators. Example: X = 4, Y = 8 Output: X = 8, Y= 4 Approach: XOR operator There are many ways to swap two...
Objective – Given a string, find the number of distinct permutations or anagrams of that string. Example: String x = “abc” Output: 6 (abc, acb, bac, bca, cab, cba) String x = “aab” Output:...
Objective: Given a string, write an algorithm to replace all the vowels with next consonant, and if last alphabet is vowel, remove it. Example: String input: “abcdefg” Output: “bbcdffg” String input: “aaaabccceee” Output: “bbbbbccc”...
What is a Spanning Tree? In an undirected and connected graph G=(V,E), a spanning tree is a subgraph that is a tree which includes all of the vertices of G, with minimum possible number of edges. A graph...
Objective: Given a graph, source vertex and destination vertex. Write an algorithm to count all possible paths between source and destination. Condition: Graph does not contain any cycle. This problem also known as “paths...
Objective: Given undirected graph write an algorithm to count the number of non reachable vertices from a given vertex Example: Approach: Use DFS Do the DFS (Depth-First Search) from the given vertex A, Recursively...
Objective: Given undirected graph write an algorithm to find out whether graph contains cycle or not. Example: Approach: Earlier we have seen how to find cycles in directed graphs. In this article we will...
