Universal Solution of Single Number Problem - The Coding Shala

Home >> Programming >> Solution of Single Number Problem

 In this post, we will learn how to solve the Single Number Problem using Bit Manipulation.

Universal Solution of Single Number Problem

Given a non-empty array of integers, every element appears n times except for one, which appears exactly once. Find that single one.

Approach

If a number appears n times then the bitSum in ith(i in range 0 to 31) vertical level equals to n or 0. For example, if 2 appears 3 times then

2 => 1 0
2 => 1 0
2 => 1 0
---------
     3 0

So if bitSum in ith level does not equal to n, then extra bit sum is coming from a single number that appears only once. In that case, the sum will be n+1(if the ith bit in a single number is 1).

So by checking all the bits sum we can find out a single number.

Java Program: 

class Solution {
    public int singleNumber(int[] nums) {
        int result = 0;
        int n = 3;
        //finding vertical sum of bits
        for(int i=0; i<32; i++) {
            int bitSum = 0;
            for(int num : nums) {
                //add 1 in sum if bit is 1
                bitSum += ((num >> i) & 1);
            }
            
            //now check if vertical sum is divided by n or not
            if(bitSum%n != 0) {
                //make ith bit as 1
                result = result | (1<<i);
            }
        }
        return result;
    }
}


Other Posts You May Like
Please leave a comment below if you like this post or found some errors, it will help me to improve my content.
By

Comments

Post a Comment

Popular Posts from this Blog

Shell Script to find sum, product and average of given numbers - The Coding Shala

Home >> Scripting >> Sum, product and average Shell Script to find the sum, product, and the average of given numbers Read four integer numbers from the user and find the sum, product, and average of these four numbers? Code:  #! / bin / bash echo "enter four integers" read a b c d sum =$(echo "$a + $b + $c + $d" | bc - l) average=$(echo "$sum / 4" | bc - l) product=$(echo "$a * $b * $c * $d" | bc - l) echo "sum = $sum" echo "Average = $average" echo "Product = $product" Other Posts You May Like Shell script to print sum of the digits of a number Shell Script to print number in descending order Shell script to find out biggest number from three numbers Shell script to find out factorial of a number Shell Script to create a simple calculator Please leave a comment below if you like this post or found some error, it will help me to improve my content.
Read more

New Year Chaos Solution - The Coding Shala

Home >> Programming Questions >> New Year Chaos New Year Chaos Problem Solution In this post, you will learn how to solve New Year Chaos Problem and implement its solution in Java. Problem:   It's New Year's Day and everyone's in line for the Wonderland rollercoaster ride! There are a number of people queued up, and each person wears a sticker indicating their initial position in the queue. Initial positions increment from at the front of the line to at the back.  Any person in the queue can bribe the person directly in front of them to swap positions. If two people swap positions, they still wear the same sticker denoting their original places in line. One person can bribe at most two others.  For Example, if n=8 and Person 5 bribes Person 4, the queue will look like this: 1,2,3,5,4,6,7,8. Fascinated by this chaotic queue, you decide you must know the minimum number of bribes that took place to get the queue into its current state. Input:
Read more

Shell Script to Create a Simple Calculator - The Coding Shala

Home >> Scripting >> simple calculator Shell Script to Create a Simple Calculator Write a shell script to create a simple calculator using a switch-case statement? Code:  #! / bin / bash echo "simple calculator" sum = 0 i = "y" echo "enter first number" read n1 echo "enter second number" read n2 while [ $ i = "y" ] do echo "1.Addition" echo "2.Subtraction" echo "3.Multiplication" echo "4.Division" echo "Enter choice" read ch case $ch in 1 ) sum =$(echo " $n1 + $n2" | bc - l) echo "Addition is =" $ sum ;; 2 ) sum =$(echo "$n1 - $n2" | bc - l) echo "Sub is =" $ sum ;; 3 ) sum =$(echo "$n1 * $n2" | bc - l) echo "Mul is =" $ sum ;; 4 ) sum =$(echo "$n1 / $n2" | bc - l) echo "div is =" $ sum ;; * )echo "invalid choice" esac echo "Do y
Read more

Java Method Overloading - The Coding Shala

Image
Home >> Learn Java >> Java Method Overloading Java Method Overloading Java class can have more than one method with the same name but different in parameters, known as Method Overloading. Question: What is the use of method overloading? Answer:  Suppose we want to perform some operation like an addition but addition can be performed between two numbers, three numbers or two floats or more. So instead of using different methods, we use the same name of the method with different parameters. This can increase the readability of the program. Method overloading can be achieved by changing numbers of arguments or by changing the data types. Example of Method Overloading in Java The following example explains Method Overloading: //Method Overloading example class Addition { public int add ( int a , int b ){ return a + b ; } public int add ( int a , int b , int c ){ return a + b + c ; }
Read more

Java Program to Convert Binary to Decimal - The Coding Shala

Home >> Java Programs >> Convert Binary to Decimal  Hey there, welcome back to another post. In this post, we will learn how to convert Binary to Decimal in Java. Java Program to Convert Binary to Decimal You have given a binary number, convert it to a decimal number. Example:  Input: 101 Output: 5 Input: 111 Output: 7 Binary to Decimal Conversion in Java Approach We will the below formula to convert binary to decimal: decimal number = (2^0) * (rightmost digit) + (2^1) * (second rightmost digit) + ...  for example:  binary number = 110 decimal number = 2^0 * 0 + 2^1 * 1 + 2^2 * 1 = 1 * 0 + 2 * 1 + 4 * 1 = 0 + 2 + 4 = 6 Java Program:  import java.util.Scanner; /** * https://www.thecodingshala.com/ */ public class Main { public static void printDecimal( int num) { int decimal = 0; int twos = 1; // 2^0 = 1 initial value while (num > 0) { int temp = num
Read more