题解 | #字符个数统计#
字符个数统计
https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
const readline = require('readline')
const r1 = readline.createInterface({
input: process.stdin,
output: process.stdout,
})
r1.on('line', function (line) {
let str = []
let str1 = [...new Set(line)]
console.log(str1.length)
})
