Find the number of pairs with odd XOR

Given an array of integers, write a program to find the number of pairs for which the XOR is an odd number. Example: Input[] = {3, 2, 1} Output: 2 Note: 1 XOR 2 = 3 and 2 XOR 3 = 1 Input[] = {3, 6, 9, 4} Output: 4 Naive Approach: Use nested loops … Read more

Evaluation of Prefix Expressions (Polish Notation) | Set 2

Earlier we had discussed how to evaluate prefix expression where operands are of single-digit. In this article, we will discuss how to evaluate prefix expression for any number ( not necessarily single digit.) Prefix notation is a notation for writing arithmetic expressions in which the operands appear after their operators. Let’s assume the below Operands … Read more

Evaluation of Prefix Expressions (Polish Notation) | Set 1

Prefix notation is a notation for writing arithmetic expressions in which the operands appear after their operators. There are no precedence rules to learn. Let’s assume the below Operands are real numbers in real digits. (Later we will Enhance the solution for any number) Permitted operators: +,-, *, /, ^(exponentiation) Blanks are NOT permitted in … Read more

Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2

Earlier we had discussed how to evaluate postfix expressions where operands are of single-digit. In this article, we will discuss how to evaluate postfix expressions for any number ( not necessarily single digit.) Postfix notation is a notation for writing arithmetic expressions in which the operands appear before their operators. Let’s assume the below Operands … Read more

Check if Arithmetic Expression contains duplicate parenthesis

Objective: Given an arithmetic expression, write an algorithm to find out whether the expression contains duplicate parenthesis. Duplicate Parenthesis: Two contiguous parentheses with no elements between them can be called as duplicate parenthesis.  Example: Input: A/(B+C)*D Output: No duplicate parenthesis found. Input: A/(B+C)*D/((E+F)) Output: duplicate parenthesis found Approach: Use Stack Iterate the given expression from … Read more

Convert Prefix to Postfix Expression

Objective: Given a Prefix expression, write an algorithm to convert it into Postfix expression. Example: Input: Prefix expression:  + A B  Output: Postfix expression: A B + Input: Prefix expression:  *-A/BC-/AKL Output: Postfix expression: ABC/-AK/L-* Approach: Use Stacks Algorithm: Iterate the given expression from right to left, one character at a time If the character … Read more

Convert Postfix to Prefix Expression

Objective: Given a Postfix expression, write an algorithm to convert it into prefix expression. Example: Input: Postfix expression:  A B +  Output: Prefix expression- + A B Input: Postfix expression:  ABC/-AK/L-* Output: Infix expression: *-A/BC-/AKL Approach: Use Stack Algorithm: Iterate the given expression from left to right, one character at a time If the character … Read more

Convert Postfix to Infix Expression

Objective: Given a Postfix expression, write an algorithm to convert it into Infix expression. Example: Input: Postfix expression:  A B +  Output: Infix expression- (A + B) Input: Postfix expression:  ABC/-AK/L-* Output: Infix expression: ((A-(B/C))*((A/K)-L)) Approach: Use Stack Algorithm: Iterate the given expression from left to right, one character at a time If a character … Read more

Convert Prefix to Infix Expression

Objective: Given a Prefix expression, write an algorithm to convert it into Infix expression. Example: Input: Prefix expression: + A B Output: Infix expression- (A + B) Input: Prefix expression: *-A/BC-/AKL Output: Infix expression: ((A-(B/C))*((A/K)-L)) Approach: Use Stacks Algorithm: Iterate the given expression from right to left (in reverse order), one character at a time … Read more

Convert Infix to Prefix Expression

Objective: Given an Infix expression, write an algorithm to convert it into Prefix expression. Example: Input: Infix expression – A + B Output: Prefix expression- +AB Input: Infix expression – A+B*(C^D-E) Output: Prefix expression- +A*B-^CDE Approach: Use Stack Operator stack: This stack will be used to keep operations (+, -, *, /, ^) Order of … Read more

Convert Infix to Postfix Expression

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- ABCD^E-*+ Approach: Use Stacks Operator stack: This stack will be used to keep operations (+, -, *, /, ^) Order of … Read more

Evaluation of Infix expressions

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 in expression. Parenthesis are permitted Example: A * ( B + C ) / D 2 * (5 + 3) / … Read more