# Toggle bits in the given range

Given a non-negative number **n** and two values **l** and **r**. The problem is to toggle the bits in the range **l** to **r** in the binary representation of **n**, i.e, to toggle bits from the rightmost **lth** bit to the rightmost **rth** bit. A toggle operation flips a bit **0** to **1** and a bit **1** to **0**.**Constraint:** 1 <= l <= r <= number of bits in the binary representation of **n**.

Examples:

Input : n = 17, l = 2, r = 3 Output : 23(17)= (10_{10}001)_{2}(23)= (10_{10}111)_{2}The bits in the range2to3in the binary representation of17are toggled. Input : n = 50, l = 2, r = 5 Output : 44

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**Approach:** Following are the steps:

- Calculate
**num as**= ((1 << r) – 1) ^ ((1 << (l-1)) – 1) or as ((1 <<r)-l). This will produce a number**num**having**r**number of bits and bits in the range**l**to**r**are the only set bits. - Now, perform
**n = n ^ num**. This will toggle the bits in the range**l**to**r**in**n**.

C/C++

```
// C++ implementation to toggle bits in
// the given range
#include <bits/stdc++.h>
using namespace std;
// function to toggle bits in the given range
unsigned int toggleBitsFromLToR(unsigned int n,
unsigned int l, unsigned int r)
{
// calculating a number 'num' having 'r'
// number of bits and bits in the range l
// to r are the only set bits
int num = ((1 << r) - 1) ^ ((1 << (l - 1)) - 1);
// toggle bits in the range l to r in 'n'
// and return the number
//Besides this, we can calculate num as: num=(1<<r)-l .
return (n ^ num);
}
// Driver program to test above
int main()
{
unsigned int n = 50;
unsigned int l = 2, r = 5;
cout << toggleBitsFromLToR(n, l, r);
return 0;
}
```

## Java

`// Java implementation to toggle bits in` `// the given range` `import` `java.io.*;` `class` `GFG` `{` ` ` `// Function to toggle bits in the given range` ` ` `static` `int` `toggleBitsFromLToR(` `int` `n, ` `int` `l, ` `int` `r)` ` ` `{` ` ` `// calculating a number 'num' having 'r'` ` ` `// number of bits and bits in the range l` ` ` `// to r are the only set bits` ` ` `int` `num = ((` `1` `<< r) - ` `1` `) ^ ((` `1` `<< (l - ` `1` `)) - ` `1` `);` ` ` ` ` `// toggle bits in the range l to r in 'n'` ` ` `// and return the number` ` ` `//Besides this, we can calculate num as: num=(1<<r)-l .` ` ` `return` `(n ^ num);` ` ` `}` ` ` ` ` `// driver program` ` ` `public` `static` `void` `main (String[] args)` ` ` `{` ` ` `int` `n = ` `50` `;` ` ` `int` `l = ` `2` `, r = ` `5` `;` ` ` `System.out.println(toggleBitsFromLToR(n, l, r));` ` ` `}` `}` `// Contributed by Pramod Kumar` |

## Python3

`# Python implementation` `# to toggle bits in` `# the given range` `# function to toggle bits` `# in the given range` `def` `toggleBitsFromLToR(n,l,r):` ` ` `# calculating a number` ` ` `# 'num' having 'r'` ` ` `# number of bits and` ` ` `# bits in the range l` ` ` `# to r are the only set bits` ` ` `num ` `=` `((` `1` `<< r) ` `-` `1` `) ^ ((` `1` `<< (l ` `-` `1` `)) ` `-` `1` `)` ` ` ` ` `# toggle bits in the` ` ` `# range l to r in 'n'` ` ` `# Besides this, we can calculate num as: num=(1<<r)-l .` ` ` `# and return the number` ` ` `return` `(n ^ num)` `# Driver code` `n ` `=` `50` `l ` `=` `2` `r ` `=` `5` `print` `(toggleBitsFromLToR(n, l, r))` `# This code is contributed` `# by Anant Agarwal.` |

## C#

`// C# implementation to toggle bits` `// in the given range` `using` `System;` `namespace` `Toggle` `{` ` ` `public` `class` `GFG` ` ` `{ ` ` ` ` ` `// Function to toggle bits in the given range` ` ` `static` `int` `toggleBitsFromLToR(` `int` `n, ` `int` `l, ` `int` `r)` ` ` `{` ` ` `// calculating a number 'num' having 'r'` ` ` `// number of bits and bits in the range l` ` ` `// to r are the only set bits` ` ` `int` `num = ((1 << r) - 1) ^ ((1 << (l - 1)) - 1);` ` ` `// toggle bits in the range l to r in 'n'` ` ` `//Besides this, we can calculate num as: num=(1<<r)-l .` ` ` `// and return the number` ` ` `return` `(n ^ num);` ` ` `}` ` ` ` ` `// Driver Code` ` ` `public` `static` `void` `Main ()` ` ` `{` ` ` `int` `n = 50;` ` ` `int` `l = 2, r = 5;` ` ` `Console.Write(toggleBitsFromLToR(n, l, r));` ` ` `}` ` ` `}` `}` `// This code is contributed by Sam007.` |

## PHP

`<?php` `// PHP implementation` `// to toggle bits in` `// the given range` `// function to toggle bits` `// in the given range` `function` `toggleBitsFromLToR(` `$n` `, ` `$l` `, ` `$r` `)` `{` ` ` ` ` `// calculating a number` ` ` `// 'num' having 'r'` ` ` `// number of bits and` ` ` `// bits in the range l` ` ` `// to r are the only` ` ` `// set bits` ` ` `$num` `= ((1 << ` `$r` `) - 1) ^` ` ` `((1 << (` `$l` `- 1)) - 1);` ` ` `// toggle bits in the` ` ` `// range l to r in 'n'` ` ` `//Besides this, we can calculate num as: $num=(1<<$r)-$l .` ` ` `// and return the number` ` ` `return` `(` `$n` `^ ` `$num` `);` `}` ` ` `// Driver Code` ` ` `$n` `= 50;` ` ` `$l` `= 2; ` `$r` `= 5;` ` ` `echo` `toggleBitsFromLToR(` `$n` `, ` `$l` `, ` `$r` `);` `// This code is contributed by anuj_67` `?>` |

## Javascript

`<script>` `// Javascript implementation to toggle bits in` `// the given range` `// function to toggle bits in the given range` `function` `toggleBitsFromLToR(n, l, r)` `{` ` ` `// calculating a number 'num' having 'r'` ` ` `// number of bits and bits in the range l` ` ` `// to r are the only set bits` ` ` `var` `num = ((1 << r) - 1) ^ ((1 << (l - 1)) - 1);` ` ` `// toggle bits in the range l to r in 'n'` ` ` `// and return the number` `//Besides this, we can calculate num as: num=(1<<r)-l .` ` ` `return` `(n ^ num);` `}` `// Driver program to test above` `var` `n = 50;` `var` `l = 2, r = 5;` `document.write( toggleBitsFromLToR(n, l, r));` `</script>` |

Output:

44

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