[google面试题]Given a sorted array of integers, how can you find the location of a particular integer x?

Good answer:Use binary search.Compare the number in the middle of the arraywith x.If it is equal,we are done.If the number is greater,we know to look in thesecond half of the array.If it is smaller,we know to look in the first half.We can repeat the search on the appropriate half of the array by comparing the middle element of that array with x,once again narrowing our search by a factor of 2.We repeat this process until we find x.This algorithm takes O(logn) time.Not‐so‐good answer:Go through each number in order and compare it to x.Thisalgorithm takes O(n) time.