题解 | #字符个数统计#
字符个数统计
https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
const rl = require("readline").createInterface({ input: process.stdin }); rl.on('line', function(line){ let arr = Array.from(new Set(line.split(''))) console.log(arr.length) })