Check if a number has bits in alternate pattern | Set 1

1.6

Given an integer n > 0, the task is to find whether this integer has an alternate pattern in its bits representation. For example- 5 has an alternate pattern i.e. 101.
Print “Yes” if it has an alternate pattern otherwise “No”. Here alternate pattern can be like 0101 or 1010.

Examples:

Input :  15
Output :  No
Explanation: Binary representation of 15 is 1111.

Input :  10
Output :  Yes
Explanation: Binary representation of 10 is 1010.

A simple approach is to find its binary equivalent and then check its bits.

C++

// C++ program to find if a number has alternate
// bit pattern
#include<bits/stdc++.h>
using namespace std;

// Returns true if n has alternate bit pattern
// else false
bool findPattern(int n)
{
    // Store last bit
    int prev = n % 2;
    n = n/2;

    // Traverse through remaining bits
    while (n > 0)
    {
        int curr = n % 2;

        // If current bit is same as previous
        if (curr == prev)
           return false;

        prev = curr;
        n = n / 2;
    }

    return true;
}

// Driver code
int main()
{
    int n = 10;
    if (findPattern(n))
        cout << "Yes";
    else
        cout << "No";

    return 0;
}

Java

// Java program to find if a number has alternate
// bit pattern

class Test
{
    // Returns true if n has alternate bit pattern
    // else false
    static boolean findPattern(int n)
    {
        // Store last bit
        int prev = n % 2;
        n = n/2;
     
        // Traverse through remaining bits
        while (n > 0)
        {
            int curr = n % 2;
     
            // If current bit is same as previous
            if (curr == prev)
               return false;
     
            prev = curr;
            n = n / 2;
        }
     
        return true;
    }
    
    // Driver method
    public static void main(String args[])
    {
        int n = 10;
        System.out.println(findPattern(n) ? "Yes" : "No");
     
    }
}


Output:

Yes

Reference:
http://stackoverflow.com/questions/38690278/program-to-check-whether-the-given-integer-has-an-alternate-pattern

This article is contributed by Sahil Chhabra (akku). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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