题解 | #统计每个月兔子的总数#

const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function (line) {
    const input = parseInt(line)
    const arr = Array.from({ length: input })
    for (let index = 0; index < input; index++) {
        if (index === 0) arr[index] = 1
        else if (index === 1) arr[index] = 0
        else {
            arr[index] = arr.slice(0, index - 1).reduce<number>((prev, cur: number) => prev + cur, 0)
        }
    }

    const total = arr.reduce<number>((prev, cur: number) => prev + cur, 0)
    console.log(total)
});