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 rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
});
rl.on("line", function (line) {
const tokens = line.split(" ");
// TODO: code start
console.log(new Set(tokens[0].split("")).size);
});