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 }); var iter = rl[Symbol.asyncIterator](); const readline = async () => (await iter.next()).value; rl.on('line',(line)=>{ console.log(new Set(line).size) })