题解 | #字符个数统计#
字符个数统计
http://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
const str=readline()
let arr=str.split("")
arr=[...new Set(arr)]
console.log(arr.length)
let arr=str.split("")
arr=[...new Set(arr)]
console.log(arr.length)