题解 | 统计字符

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

async function main() {
    let input = await readline();
    // 初始化计数器
    let letterCount = 0;
    let spaceCount = 0;
    let digitCount = 0;
    let otherCount = 0;

    // 遍历字符串并统计各类字符的数量
    for (const char of input) {
        if (/[a-zA-Z]/.test(char)) {
            letterCount++;
        } else if (char === ' ') {
            spaceCount++;
        } else if (/\d/.test(char)) {
            digitCount++;
        } else {
            otherCount++;
        }
    }

    // 输出结果
    console.log(letterCount);
    console.log(spaceCount);
    console.log(digitCount);
    console.log(otherCount);
}

main();