[2020 KAKAO TECH INTERNSHIP Level 3] 보석 쇼핑

function solution(gems) {
    const types = new Set(gems).size;
    const count = {};
 
    let start = 0, end = 0, contained = 0;
    let range = [0, gems.length - 1];
 
    const add = (gem) => {
        if (!count[gem]) count[gem] = 0;
        if (count[gem]++ === 0) contained++;
    };
 
    const del = (gem) => {
        if(--count[gem] === 0) contained--;
    }
 
    add(gems[start]);
 
    while(start < gems.length && end < gems.length){
        if(types === contained){
            if(range[1] - range[0]  > end - start){
                range = [start, end];
            }
 
            del(gems[start++]);
        } else {
            add(gems[++end]);
        }
    }
 
    // ✅ 1-Based Indexing
    return range.map(idx => idx + 1);
}