update readme

Author: kumar91gopi

FixedPointInSorted.rb

@@ -0,0 +1,28 @@
+=begin
+Given an array of n distinct integers sorted in ascending order, find a fixed point in the array.
+Fixed Point in an array is an index i such that arr[i] is equal to i, i.e. a[i]==i
+Time-complexity: O(logn)
+Space-complexity: O(1)
+Algorithm: Binary Search
+=end
+
+def fixed_point(a)
+    n=a.length
+    hi=n-1
+    lo=0
+    while(hi>=lo)
+        mid=lo+(hi-lo)/2
+        
+        if a[mid]==mid
+            return mid
+        elsif a[mid]<mid
+            lo=mid+1
+        else
+            hi=mid-1
+        end
+    end
+    
+    #if no fixed point exists
+    return -1
+
+end

FixedPointInUnsorted.rb

@@ -0,0 +1,17 @@
+=begin
+Given an array, find a fixed point in the array.
+Fixed Point in an array is an index i such that arr[i] is equal to i, i.e. a[i]==i
+Time-complexity: O(n)
+Space-complexity: O(1)
+Algorithm: Linear Search
+=end
+def fixed_point(a)
+    n=a.length
+    for i in 0...n
+        if a[i]==i
+            return i
+        end
+    end
+    #if no fixed point exists
+    return -1
+end

README.md

@@ -41,6 +41,10 @@ The solutions are easy to understand and complete.
     b.[Fitcher-Yates shuffling Algorithm)](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/FitcherYatesShufflingAlgorithm.rb)
 6. [Find pair in array with sum equal to given sum](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/ChekPairWithGivenSum.rb)
 7. [Find equilibrium index in an array](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/EquilibriumIndexofArray.rb)
+8. Find fixed point in an array
+    * [fixed point in unsorted array](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/FixedPointInUnsorted.rb)
+    * [fixed point in sorted array](https://github.com/kumar91gopi/Algorithms-and-Data-Structures-in-Ruby/blob/master/FixedPointInSorted.rb)
+