Question

Write a function that counts how many unique characters appear more than once?
function solve( a ){ //write your code here }
Login to Submit

String: "hello"
'h' appears 1 time    , 'e' appears 1 time    ,   'l' appears 2 times   ,  'o' appears 1 time
Only 'l' appears more than once.so output =1

input:xqzojGDO
ouput:0

input:diS1oWegyjyO
ouput:1