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# Print n 0s and m 1s such that no two 0s and no three 1s are together

• Last Updated : 11 May, 2021

Given two integers n and m where n is the number of 0s and m is the number of 1s. The task is to print all the 0s and 1s in a single row such that no two 0s are together and no three 1s are together. If it’s not possible to arrange 0s and 1s according to the condition then print -1.
Examples:

Input: n = 1, m = 2
Output: 011
Input: n = 4, m = 8
Output: 110110110101

Approach: We have answers only when, ( (n – 1) ≤ m and m ≤ 2 * (n + 1)

• If (m == n – 1) then print the pattern 010101… starting from 0 until all the 0s and 1s have been used.
• If (m > n) and m ≤ 2 * (n + 1) then print the pattern 110110110… until there is excessive 1s and change to pattern 0101010… when m becomes equal to n – 1.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function to print the required pattern``void` `printPattern(``int` `n, ``int` `m)``{` `    ``// When condition fails``    ``if` `(m > 2 * (n + 1) || m < n - 1) {``        ``cout << ``"-1"``;``    ``}` `    ``// When m = n - 1``    ``else` `if` `(``abs``(n - m) <= 1) {``        ``while` `(n > 0 && m > 0) {``            ``cout << ``"01"``;``            ``n--;``            ``m--;``        ``}``        ``if` `(n != 0) {``            ``cout << ``"0"``;``        ``}``        ``if` `(m != 0) {``            ``cout << ``"1"``;``        ``}``    ``}``    ``else` `{``        ``while` `(m - n > 1 && n > 0) {``            ``cout << ``"110"``;``            ``m = m - 2;``            ``n = n - 1;``        ``}``        ``while` `(n > 0) {``            ``cout << ``"10"``;``            ``n--;``            ``m--;``        ``}``        ``while` `(m > 0) {``            ``cout << ``"1"``;``            ``m--;``        ``}``    ``}``}` `// Driver program``int` `main()``{``    ``int` `n = 4, m = 8;``    ``printPattern(n, m);``    ``return` `0;``}`

## Java

 `// Java implementation of the above approach``class` `GFG``{``    ``// Function to print the required pattern``    ``static` `void` `printPattern(``int` `n, ``int` `m)``    ``{``        ``// When condition fails``        ``if` `(m > ``2` `* (n + ``1``) || m < n - ``1``)``        ``{``            ``System.out.print(``"-1"``);``        ``}``        ` `        ``// When m = n - 1``        ``else` `if` `(Math.abs(n - m) <= ``1``)``        ``{``            ``while` `(n > ``0` `&& m > ``0``)``            ``{``                ``System.out.print(``"01"``);``                ``n--;``                ``m--;``                ` `            ``}``            ``if` `(n != ``0``)``            ``{``                ``System.out.print(``"0"``);``            ``}``            ``if` `(m != ``0``)``            ``{``                ``System.out.print(``"1"``);``            ``}``        ``}``        ``else``        ``{``            ``while` `(m - n > ``1` `&& n > ``0``)``            ``{``                ``System.out.print(``"110"``);``                ``m = m - ``2``;``                ``n = n - ``1``;``            ``}``            ``while` `(n > ``0``)``            ``{``                ``System.out.print(``"10"``);``                ``n--;``                ``m--;``            ``}``            ``while` `(m > ``0``)``            ``{``                ``System.out.print(``"1"``);``                ``m--;``            ``}``        ``}``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String []args)``    ``{``        ``int` `n = ``4``, m = ``8``;``        ``printPattern(n, m);``    ``}``}` `// This code is contributed by Ita_c.`

## Python3

 `# Python 3 implementation of the approach` `# Function to print the required pattern``def` `printPattern(n, m):``    ` `    ``# When condition fails``    ``if` `(m > ``2` `*` `(n ``+` `1``) ``or` `m < n ``-` `1``):``        ``print``(``"-1"``, end ``=` `"")` `    ``# When m = n - 1``    ``elif` `(``abs``(n ``-` `m) <``=` `1``):``        ``while` `(n > ``0` `and` `m > ``0``):``            ``print``(``"01"``, end ``=` `"");``            ``n ``-``=` `1``            ``m ``-``=` `1``        ` `        ``if` `(n !``=` `0``):``            ``print``(``"0"``, end ``=` `"")``        ``if` `(m !``=` `0``):``            ``print``(``"1"``, end ``=` `"")``    ``else``:``        ``while` `(m ``-` `n > ``1` `and` `n > ``0``):``            ``print``(``"110"``, end ``=` `"")``            ``m ``=` `m ``-` `2``            ``n ``=` `n ``-` `1``        ` `        ``while` `(n > ``0``):``            ``print``(``"10"``, end ``=` `"")``            ``n ``-``=` `1``            ``m ``-``=` `1``        ` `        ``while` `(m > ``0``):``            ``print``(``"1"``, end ``=` `"")``            ``m ``-``=` `1``    ` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:``    ``n ``=` `4``    ``m ``=` `8``    ``printPattern(n, m)` `# This code is contributed by``# Surendra_Gangwar`

## C#

 `// C# implementation of the above approach``using` `System;` `class` `GFG``{``    ``// Function to print the required pattern``    ``static` `void` `printPattern(``int` `n, ``int` `m)``    ``{``        ``// When condition fails``        ``if` `(m > 2 * (n + 1) || m < n - 1)``        ``{``            ``Console.Write(``"-1"``);``        ``}``        ``// When m = n - 1``        ``else` `if` `(Math.Abs(n - m) <= 1)``        ``{``            ``while` `(n > 0 && m > 0)``            ``{``                ``Console.Write(``"01"``);``                ``n--;``                ``m--;``                ` `            ``}``            ``if` `(n != 0)``            ``{``                ``Console.Write(``"0"``);``            ``}``            ``if` `(m != 0)``            ``{``                ``Console.Write(``"1"``);``            ``}``        ``}``        ``else``        ``{``            ``while` `(m - n > 1 && n > 0) ``            ``{``                ``Console.Write(``"110"``);``                ``m = m - 2;``                ``n = n - 1;``            ``}``            ``while` `(n > 0)``            ``{``                ``Console.Write(``"10"``);``                ``n--;``                ``m--;``            ``}``            ``while` `(m > 0)``            ``{``                ``Console.Write(``"1"``);``                ``m--;``            ``}``        ``}``    ``}` `    ``// Driver code``    ``public` `static` `void` `Main()``    ``{``        ``int` `n = 4, m = 8;``        ``printPattern(n, m);``    ``}``}` `// This code is contributed by Ryuga`

## PHP

 ` 2 * (``\$n` `+ 1) || ``\$m` `< ``\$n` `- 1)``    ``{``        ``echo``(``"-1"``);``    ``}``    ` `    ``// When m = n - 1``    ``else` `if` `(``abs``(``\$n` `- ``\$m``) <= 1)``    ``{``        ``while` `(``\$n` `> 0 && ``\$m` `> 0)``        ``{``            ``System.out.``print``(``"01"``);``            ``\$n``--;``            ``\$m``--;``            ` `        ``}``        ``if` `(``\$n` `!= 0)``        ``{``            ``echo``(``"0"``);``        ``}``        ``if` `(``\$m` `!= 0)``        ``{``            ``echo``(``"1"``);``        ``}``    ``}``    ``else``    ``{``        ``while` `(``\$m` `- ``\$n` `> 1 && ``\$n` `> 0)``        ``{``            ``echo``(``"110"``);``            ``\$m` `= ``\$m` `- 2;``            ``\$n` `= ``\$n` `- 1;``        ``}``        ``while` `(``\$n` `> 0)``        ``{``            ``echo``(``"10"``);``            ``\$n``--;``            ``\$m``--;``        ``}``        ``while` `(``\$m` `> 0)``        ``{``            ``echo``(``"1"``);``            ``\$m``--;``        ``}``    ``}``}` `// Driver code``\$n` `= 4; ``\$m` `= 8;    ``printPattern(``\$n``, ``\$m``);` `// This code is contributed by``// Mukul Singh.``?>`

## Javascript

 ``
Output
`110110110101`

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