개발야옹

https://www.acmicpc.net/problem/10808

const fs = require('fs');
const input = fs.readFileSync('/dev/stdin').toString().trim().split("");
const answer = [];

const dic = {
    a: 0,
    b: 0,
    c: 0,
    d: 0,
    e: 0,
    f: 0,
    g: 0,
    h: 0,
    i: 0,
    j: 0,
    k: 0,
    l: 0,
    m: 0,
    n: 0,
    o: 0,
    p: 0,
    q: 0,
    r: 0,
    s: 0,
    t: 0,
    u: 0,
    v: 0,
    w: 0,
    x: 0,
    y: 0,
    z: 0,
}

input.forEach((d) => {
    if(dic[d] !== undefined ) dic[d]++;
});

const keyList = Object.keys(dic);

keyList.forEach((key) => {
    answer.push(dic[key]);
});

console.log(answer.join(" "));

https://www.acmicpc.net/problem/2744

const fs = require('fs');
const input = fs.readFileSync('/dev/stdin').toString().trim().split("");

input.forEach((i, index) => {
    if(i.charCodeAt() >= 65 && i.charCodeAt() <= 90) {
        input[index] = String.fromCharCode(i.charCodeAt()+32);
    } else {
        input[index] = String.fromCharCode(i.charCodeAt()-32);
    }
})

console.log(input.join(""));

https://www.acmicpc.net/problem/2750

const fs = require('fs');
const input = fs.readFileSync('/dev/stdin').toString().split("\n");

const N = Number(input[0]);
const list = [];

for(let i= 0; i < N ; i++) {
    list.push(Number(input[1+i]));
}

list.sort();
list.forEach((l) => {
    console.log(l);
});

https://www.acmicpc.net/problem/1316

const fs = require('fs');
const input = fs.readFileSync('/dev/stdin').toString().split("\n");

const N = Number(input[0]);
let answer = 0;

for(let i = 0 ; i < N ; i++) {
    let cnt = 0;
    let view = [];
    const tmp = input[i+1].split("");
    let prev = '';
    tmp.forEach((t, index) => {
        if(index === 0) prev = t;
        if(prev !== t && !view.includes(t)) {
            view.push(prev);
            prev = t;
        }
        if(view.includes(t)) {
            cnt++;
        }
    });
    if(cnt > 0) answer++; 
}

console.log(N-answer);