FastPrep
Problem · String

Find First Unique 🍉

● EasyINTERNOA
See Amazon online assessment and hiring insights

Amazon Web Services is experimenting with optimizing search queries based on the location of the first unique character in a search. You have been asked to help test the query your team has created to ensure it works as designed. A unique character is one which appears only once in a string. Given a string consisting of lowercase English letters only, return the index of the first occurrence of a unique character in the string using 1-based indexing. If the string does not contain any unique character, return -1.

Function Description

Complete the function findFirstUnique in the editor below.

findFirstUnique has the following parameter(s):

  • string s: a string

Returns

int: either the 1-based index or -1

Examples
01 · Example 1
s = "statistics"
return = 3
The unique characters are [a, c] among which a occurs first. Using 1-based indexing, it is at index 3.
Constraints
  • 1 <= len of s <= 105
  • The string s consists of lowercase English letters only.
    • More Amazon problems
    drafts saved locally
    public int findFirstUnique(String s) {
  // write your code here
}
    s"statistics"
    expected3
    sign in to submit