Copy set bits in a range.cpp

Coding/copy_set_bits_in_range.cpp

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+//Copy set bits in a range
+//Given two numbers x and y, and a range [l, r] where 1 <= l, r <= 32. The task is consider set bits of y in range [l, r] and set these bits in x also.
+
+#include <iostream>
+using namespace std;
+//https://www.geeksforgeeks.org/copy-set-bits-in-a-range/
+
+// Copying set bits in range [left, right] from b to a. Kindly note that a is passed by reference and modified by this function.
+void CopyingSetBits(unsigned &a, unsigned b,
+                 unsigned left, unsigned right)
+{
+    if (left < 1 || right > 32)
+        return ;
+
+    // here we get the length of the mask
+    int maskLength = (1ll<<(right-left+1)) - 1;
+
+    // Shifting the mask to the required position
+    // "&" with b to get the set bits at between left and right in b
+    int m = ((maskLength)<<(left-1)) & b ;
+    a = a | m;
+}
+
+int main()
+{
+   unsigned a, b, left, right;
+   cout<<"Enter the value of x and y respectively: ";
+   cin>>a>>b;
+   cout<<"Enter the value of left and right respectively: ";
+   cin>>left>>right;
+   CopyingSetBits(a, b, left, right);
+   cout << "Modified x is " << a;
+   return 0;
+}
+
+//Time Complexity: O(r)
+//Auxiliary Space: O(1)