feat: add Next Higher Number with same set bits (#2484)

* Next higher number with same set bits implimented

* Added to DIRECTORY.md

* Update bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp

new line aded

Co-authored-by: David Leal <[email protected]>

* Update bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp

* added

Co-authored-by: David Leal <[email protected]>

* Update bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp

recomendation added

Co-authored-by: David Leal <[email protected]>

* Update next_higher_number_with_same_number_of_set_bits.cpp

int to int64_t

* Update bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp

Co-authored-by: realstealthninja <[email protected]>

---------

Co-authored-by: David Leal <[email protected]>
Co-authored-by: realstealthninja <[email protected]>

DIRECTORY.md

@@ -20,6 +20,7 @@
   * [Count Of Trailing Ciphers In Factorial N](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/count_of_trailing_ciphers_in_factorial_n.cpp)
   * [Find Non Repeating Number](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/find_non_repeating_number.cpp)
   * [Hamming Distance](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/hamming_distance.cpp)
+  * [next higher number with same number of set bits](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp)
   * [Power Of 2](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/power_of_2.cpp)
   * [Set Kth Bit](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/set_kth_bit.cpp)
   * [Travelling Salesman Using Bit Manipulation](https://github.com/TheAlgorithms/C-Plus-Plus/blob/HEAD/bit_manipulation/travelling_salesman_using_bit_manipulation.cpp)

bit_manipulation/next_higher_number_with_same_number_of_set_bits.cpp

@@ -0,0 +1,103 @@
+/**
+ * @file
+ * @brief [Next higher number with same number of set bits]
+ * (https://www.geeksforgeeks.org/next-higher-number-with-same-number-of-set-bits/)
+ * implementation
+ *
+ * @details
+ * Given a number x, find next number with same number of 1 bits in it’s binary representation.
+ * For example, consider x = 12, whose binary representation is 1100 (excluding leading zeros on 32 bit machine).
+ * It contains two logic 1 bits. The next higher number with two logic 1 bits is 17 (100012).
+ *
+ * A binary number consists of two digits. They are 0 & 1. Digit 1 is known as
+ * set bit in computer terms.
+ * @author [Kunal Nayak](https://github.com/Kunal766)
+ */
+
+#include <cassert>   /// for assert
+#include <iostream>  /// for IO operations
+
+/**
+ * @namespace bit_manipulation
+ * @brief Bit manipulation algorithms
+ */
+namespace bit_manipulation {
+
+/**
+ * @brief The main function implements checking the next number
+ * @param x the number that will be calculated
+ * @returns a number
+ */
+uint64_t next_higher_number(uint64_t x)
+{
+
+  uint64_t rightOne;
+  uint64_t nextHigherOneBit;
+  uint64_t rightOnesPattern;
+
+  uint64_t next = 0;
+
+  if(x)
+  {
+
+    // right most set bit
+    rightOne = x & -(signed)x;
+
+    // reset the pattern and set next higher bit
+    // left part of x will be here
+    nextHigherOneBit = x + rightOne;
+
+    // nextHigherOneBit is now part [D] of the above explanation.
+
+    // isolate the pattern
+    rightOnesPattern = x ^ nextHigherOneBit;
+
+    // right adjust pattern
+    rightOnesPattern = (rightOnesPattern)/rightOne;
+
+    // correction factor
+    rightOnesPattern >>= 2;
+
+    // rightOnesPattern is now part [A] of the above explanation.
+
+    // integrate new pattern (Add [D] and [A])
+    next = nextHigherOneBit | rightOnesPattern;
+  }
+
+  return next;
+}
+
+}  // namespace bit_manipulation
+
+/**
+ * @brief Self-test implementations
+ * @returns void
+ */
+static void test() {
+    // x = 4 return 8
+    assert(bit_manipulation::next_higher_number(4) == 8);
+    // x = 6 return 9
+    assert(bit_manipulation::next_higher_number(6) == 9);
+    // x = 13 return 14
+    assert(bit_manipulation::next_higher_number(13) == 14);
+    // x = 64 return 128
+    assert(bit_manipulation::next_higher_number(64) == 128);
+    // x = 15 return 23
+    assert(bit_manipulation::next_higher_number(15) == 23);
+    // x= 32 return 64
+    assert(bit_manipulation::next_higher_number(32) == 64);
+    // x = 97 return 98
+    assert(bit_manipulation::next_higher_number(97) == 98);
+    // x = 1024 return 2048
+    assert(bit_manipulation::next_higher_number(1024) == 2048);
+
+    std::cout << "All test cases have successfully passed!" << std::endl;
+}
+/**
+ * @brief Main function
+ * @returns 0 on exit
+ */
+int main() {
+    test();  // run self-test implementations
+    return 0;
+}