Find position of set bit using C++

Author: raunakpandey1

Bit Manipulation/Find_position_of_set_bit.cpp

@@ -0,0 +1,61 @@
+
+/*
+Given a number N having only one ‘1’ and all other ’0’s in its binary representation, find position of the only set bit. If there are 0 or more than 1 set bit the answer should be -1. Position of  set bit '1' should be counted starting with 1 from LSB side in binary representation of the number.
+
+Example 1:
+
+Input:
+N = 2
+Output:
+2
+Explanation:
+2 is represented as "10" in Binary.
+As we see there's only one set bit
+and it's in Position 2 and thus the
+Output 2.*/
+#include <bits/stdc++.h>
+using namespace std;
+ 
+
+class Solution {
+  public:
+  
+  int isPowerOfTwo(unsigned N) 
+    { 
+        return N && (!(N & (N - 1))); 
+    } 
+    int findPosition(int N) {
+        // code here
+        if (!isPowerOfTwo(N)) 
+            return -1; 
+  
+        unsigned i = 1, pos = 1; 
+      
+        
+        while (!(i & N)) { 
+            
+            i = i << 1; 
+      
+            // increment position 
+            ++pos; 
+        } 
+      
+        return pos; 
+        
+        }
+};
+
+// { Driver Code Starts.
+int main() {
+    int t;
+    cin >> t;
+    while (t--) {
+        int N;
+
+        cin>>N;
+
+        Solution ob;
+        cout << ob.findPosition(N) << endl;
+    }
+    return 0;
+}  // } Driver Code Ends