find-center-of-star-graph_0226.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>find-center-of-star-graph</title>
</head>
<body>
    
</body>
<script>
const edges = [[1,2],[2,3],[4,2]];

console.log(findCenter(edges));

/**
 * @param {number[][]} edges
 * @return {number}
 */


/**
 * @param {number[][]} edges
 * @return {number}
 */
function findCenter(edges) {
    let result = edges[0][0];
    
    edges.forEach((edge, index) => {  
        if(!edge.includes(edges[0][0])) {
            result = edges[0][1]
        }
    })
    return result
};

// Way2
// function findCenter(edges) {
//     let ht = {}
//     let result = 0;
    
//     edges.forEach((edge)=>{
//         edge.forEach((num)=>{
//             ht[num] = ht[num] + 1 || 1
//         })
//     })
    
//     for (let key in ht ) {
//         if(ht[key] === edges.length) result = key
//     }
    
//     return result
// };

</script>
</html>