题解 | #汽水瓶#

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

void (async function () {
    // Write your code here
    while ((line = await readline())) {
        if (line === "0") return;
        let count = 0;
        let n = parseInt(line);
        // 2个
        if (n === 2) {
            count += 1;
        }
        while (n >= 3) {
            // 换一次，又得到 i 个空瓶子
            let i = Math.floor(n / 3);
            // 换一次，剩下 j 个空瓶子
            let j = n % 3;
            // 记录喝了的总数
            count += i;
            // 剩下的总空瓶子数
            n = i + j; // 大于等于3个接着换
            // 2个就借一个换一个
            if (n === 2) {
                count += 1;
            }
        }
        console.log(count);
    }
})();