Merge pull request #669 from neha030/dev16

Rotate Bits added

Author: Saviour1001

Bit Manipulation/rotate_bits.cpp

@@ -0,0 +1,76 @@
+/*A rotation (or circular shift) is an operation similar to shift except that the
+bits that fall off at one end are put back to the other end. 
+In left rotation, the bits that fall off at left end are put back at right end. 
+In right rotation, the bits that fall off at right end are put back at left end.
+*/
+
+#include <bits/stdc++.h> 
+using namespace std; 
+
+// Left Rotate 'cnt' number of bits of the given number 'n'
+int left_rotate_bits(int n, int cnt)
+{
+    int msb;
+    
+    // 32 is the total number of bits used to store an INT variable in C++
+    for(cnt = cnt % 31;cnt>0;cnt--)
+    {
+        //Store the current MSB in a temporary variable
+        msb = (n >> 31) & 1;
+        //Left rotate the given number by one bit
+        n = (n<<1);
+        //Set the dropped MSB as the new LSB
+        n = n | msb;
+    }
+    return n;
+}
+
+// Right Rotate 'cnt' number of bits of the given number 'n'
+int right_rotate_bits(int n, int cnt)
+{
+    int lsb;
+    
+    // 32 is the total number of bits used to store an INT variable in C++
+    for(cnt = cnt % 31;cnt>0;cnt--)
+    {
+        //Store the current LSB in a temporary variable
+        lsb = n & 1;
+        //Right rotate the given number by one bit and drop its LSB
+        n = (n >> 1) & (~(1 << 31));
+        //Set the dropped LSB as the new MSB
+        n = n | (lsb << 31);
+    }
+    return n;
+}
+
+
+int main()
+{
+    int n,cnt,left,right;
+    cout<<"\nEnter the number : ";
+    cin>>n;
+
+    cout<<"How many bits do you want to rotate : ";
+    cin>>cnt;
+  
+    //Call the sort function 
+    left = left_rotate_bits(n, cnt);  
+    right = right_rotate_bits(n,cnt);
+
+    cout<<"The Left-rotated number is : "<<left<<endl;
+    cout<<"The Right-rotated number is : "<<right<<endl;
+
+    return 0;
+}
+
+/*
+INPUT 
+Enter the number : 39
+How many bits do you want to rotate : 17
+OUTPUT
+The Left-rotated number is : 5111808 
+The Right-rotated number is : 1277952
+
+Time Complexity: O(n)
+Space Complexity: O(1)
+*/