@^^ many solution to this problem in O(n) METHOD 1(Use sum formula)
Algorithm: 1. Get the sum of numbers total = n*(n+1)/2 2 Subtract all the numbers from sum and you will get the missing number. Time Complexity: O(n) METHOD 2(Use XOR) 1) XOR all the array elements, let the result of XOR be X1. 2) XOR all numbers from 1 to n, let XOR be X2. 3) XOR of X1 and X2 gives the missing number. Time Complexity: O(n) Correct me If I am Wrong Thanks & Regards Shashank Mani >> ""The best way to escape from a problem is to solve it."" -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.