题解 | #【模板】循环队列#

const readline = require("readline");

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});
let len: number = 1;
let arr:string[] = [];
rl.on("line", function (line) {
    const tokens = line.split(" ");
    let one = tokens[0];
    if (one == "push") {
        if(arr.length < len){
            arr.push(tokens[1]);
        }else console.log('full');
    }
    else if (one == "pop") {
        if (arr.length) {
            console.log(arr.shift());
        } else console.log("empty");
    } else if (one == "front") {
        if (arr.length) {
            console.log(arr[0]);
        } else console.log("empty");
    }else len = parseInt(one);
});