스킬트리

const solution = (skill, skill_trees) => {
    let answer = 0;
    const skillChar = new Map();
    
    for(let i = 0; i < skill.length; i++){
        if(!skillChar.has(skill[i])){
            skillChar.set(skill[i], true);
        }
    }
    
    for(let i = 0; i < skill_trees.length; i++){
        const currentSkill = skill_trees[i];
        let skillIndex = 0;
        let isRight = true;
        
        for(let j = 0; j < currentSkill.length; j++){
            if(!skillChar.has(currentSkill[j])){
                continue;
            }
            
            if(currentSkill[j] !== skill[skillIndex++]){
                isRight = false;
                break;
            }
        }
        
        if(isRight){
            answer++;
        }
    }
    
    return answer;
}

const solution = (skill, skill_trees) => {
  let answer = 0;

  for (let skillTree of skill_trees) {
    const filteredTree = [...skillTree] // 배열로 만들기 위함.
      .filter((s) => [...skill].includes(s)) // cbaf - cb -> cbd
      .join("");
    const filteredSkill = [...skill].slice(0, filteredTree.length).join("");

    if (filteredSkill === filteredTree) answer += 1;
  }

  return answer;
};

function solution(skill, skill_trees) {
    const splitSkill = skill.split('');
    let answer = 0;
    
    skill_trees.forEach(skill_tree => {
        const splitSkillTree = skill_tree.split('');
        let check = 0, canPass = true;
        
        for(const char of splitSkillTree) {
            if(splitSkill.includes(char)) {
                if(check === splitSkill.indexOf(char)) {
                    check++;
                }
                else {
                    canPass = false;
										break;
                }
            }
        }
        if(canPass) answer++;
    });
    
    return answer;
}