prim算法是求求最小生成树的一种贪心算法，而且代码与dijkstra算法非常类似，不同的地方是dijkstra算法每次寻找和更新是所有已知点的距离到源点的最小距离， 而prim算法每次寻找的是现有最小生成树的所有的不在生成树上的临近点的最小距离。
const INF = Number.MAX_SAFE_INTEGER; const minKey = (key, visited) => { let min = INF; let minIndex = -1; for (let i = 0; i < visited.length; i++) { if (!visited[i] && key[i] < min) { min = key[i]; minIndex = i; } } return minIndex; } const prim = (graph) => { const key = []; //用来保存到父节点的距离 const parent = []; //用来保存父节点是谁 const visited = []; //用来保存某个点是否已经加入了最小生成树中 const length = graph.length; for (let i = 0; i < length; i++) { key[i] = INF; visited[i] = false; } parent[0] = -1; key[0] = 0; for (let i = 0; i < length - 1; i++) { const u = minKey(key, visited); visited[u] = true; for (let v = 0; v < length; v++) { if (!visited[v] && graph[u][v] && graph[u][v] < key[v]) { key[v] = graph[u][v]; parent[v] = u; } } } return { parent, key }; } const graph = [[0, 2, 4, 0, 0, 0], [2, 0, 2, 4, 2, 0], [4, 2, 0, 0, 3, 0], [0, 4, 0, 0, 3, 2], [0, 2, 3, 3, 0, 2], [0, 0, 0, 2, 2, 0]]; const result = prim(graph); console.dir(result);