Binary Swap
Tag(s):

## Algorithms, Easy, String, String Manipulation

Problem
Editorial
Analytics

You are given two binary strings A and B of equal length. You have a type of opertion in which you can swap any two elements of string B. Your task is to find the minimum number of operations required to convert string B into string A. If it is not possible, print -1.

Input Format:

First line contains string A.

Second line contains string B.

Output Format:

Print the minimum number of operations required to convert string B into string A. If it is not possible, print -1.

Constraints:

$|A| = |B| ; |S| \; refers \; to \; length \; of \; string \; S$

$1 \le |A| \le 10^5$

SAMPLE INPUT
1110
1101

SAMPLE OUTPUT
1

Explanation

You can swap the last and second last element in the string B. After swapping string B will become 1110. Therefore, only one operation is required to convert string B into string A.

Time Limit: 1.0 sec(s) for each input file.
Memory Limit: 256 MB
Source Limit: 1024 KB
Marking Scheme: Marks are awarded when all the testcases pass.
Allowed Languages: Bash, C, C++, C++14, Clojure, C#, D, Erlang, F#, Go, Groovy, Haskell, Java, Java 8, JavaScript(Rhino), JavaScript(Node.js), Julia, Kotlin, Lisp, Lisp (SBCL), Lua, Objective-C, OCaml, Octave, Pascal, Perl, PHP, Python, Python 3, R(RScript), Racket, Ruby, Rust, Scala, Swift, Swift-4.1, TypeScript, Visual Basic

## CODE EDITOR

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## This Problem was Asked in Challenge Name

Tata Health Java Hiring Challenge

OTHER PROBLEMS OF THIS CHALLENGE
• Algorithms > Greedy Algorithms
• Data Structures > Arrays