[프로그래머스] Lv3. 섬 연결하기 - Javascript

문제링크

문제풀이

function solution(n, costs) {
    let answer =0;
    costs.sort((a,b)=>a[0]===b[0]?a[1]-b[1]:a[0]-b[0]);
    let edge=Array.from({length:n},()=>Array());
    let vertex=new Set();
    costs.forEach((cost)=>{
         vertex.add(cost[0]).add(cost[1]);
    })
    vertex=[...vertex];
    costs.forEach((cost)=>{
         let x=vertex.indexOf(cost[0]);
         let y=vertex.indexOf(cost[1]);
         let w=cost[2];
         edge[x].push([w,y]);
         edge[y].push([w,x]); 
    })
    let checked=Array(n).fill(0);
    let heap=[[0,0]];
    while (heap.length){
        let [w, node]=heap.shift();
        if(!checked[node]){
            checked[node]=1;
            answer+=w;
        }
        for(let e of edge[node]){
            let w=e[0];
            let nextnode=e[1];
            if(!checked[nextnode]){
                heap.push([w,nextnode]);
            }
        }
        heap.sort((a,b)=>a[0]-b[0]);
    }
    return answer;
}