普里姆演算法列印最小生成樹：

∞ 我們程式碼中用65535表示

//定義鄰接矩陣
let Arr2 = [
    [0, 10, 65535, 65535, 65535, 11, 65535, 65535, 65535],
    [10, 0, 18, 65535, 65535, 65535, 16, 65535, 12],
    [65535, 65535, 0, 22, 65535, 65535, 65535, 65535, 8],
    [65535, 65535, 22, 0, 20, 65535, 65535, 16, 21],
    [65535, 65535, 65535, 20, 0, 26, 65535, 7, 65535],
    [
 
11, 65535, 65535, 65535, 26, 0, 17, 65535, 65535],
    [65535, 16, 65535, 65535, 65535, 17, 0, 19, 65535],
    [65535, 65535, 65535, 16, 7, 65535, 19, 0, 65535],
    [65535, 12, 8, 21, 65535, 65535, 65535, 65535, 0],
]

let numVertexes = 9, //定義頂點數
    numEdges = 15; //定義邊數

// 定義圖結構  
function MGraph() {
    
 
this.vexs = []; //頂點表
    this.arc = []; // 鄰接矩陣，可看作邊表
    this.numVertexes = null; //圖中當前的頂點數
    this.numEdges = null; //圖中當前的邊數
}
let G = new MGraph(); //建立圖使用

//建立圖
function createMGraph() {
    G.numVertexes = numVertexes; //設定頂點數
    G.numEdges = numEdges; //設定邊數

    //錄入頂點資訊
    for (let i = 0; i < G.numVertexes; i++) {
        G.vexs[i] 
 
= 'V' + i; //scanf('%s'); //ascii碼轉字元 //String.fromCharCode(i + 65);
    }
    console.log(G.vexs) //列印頂點

    //鄰接矩陣初始化
    for (let i = 0; i < G.numVertexes; i++) {
        G.arc[i] = [];
        for (j = 0; j < G.numVertexes; j++) {
            G.arc[i][j] = Arr2[i][j]; //INFINITY; 
        }
    }
    console.log(G.arc); //列印鄰接矩陣
}

function MiniSpanTree_Prim() {
    let min, i, j, k;
    let adjvex = []; // 儲存相關頂點下標
    let lowcost = []; // 儲存相關頂點間的權值
    for (i = 0; i < G.numVertexes; i++) {
        lowcost[i] = G.arc[0][i]; //將V0頂點與之有邊的權的權值存入陣列
        adjvex[i] = 0; //初始化都為v0的下標
    }

    for (i = 1; i < G.numVertexes; i++) {
        min = 65535;
        j = 0;
        k = 0;
        while (j < G.numVertexes) {
            if (lowcost[j] != 0 && lowcost[j] < min) { //如果權值不為0且小於min
                min = lowcost[j];
                k = j;
            }
            j++;
        }
        lowcost[k] = 0; //將當前頂點的權值設定為0，表示此頂點已完成任務
        // console.log('(%d,%d,%d)', adjvex[k], k, min); //列印當前頂點邊中權值最小邊,和權值
        console.log('(%s,%s,%d)', G.vexs[adjvex[k]], G.vexs[k], min);  //列印頂點名稱和權值
        for (j = 0; j < G.numVertexes; j++) { //迴圈所有頂點
            if (lowcost[j] != 0 && G.arc[k][j] < lowcost[j]) { //若下標為k頂點各邊權值小於此前這些頂點未被加入生成樹權值
                lowcost[j] = G.arc[k][j]; //將較小權值存入 lowcost
                adjvex[j] = k;
            }

        }
    }
}


createMGraph();
console.log('**********列印最小生成樹*********');
MiniSpanTree_Prim();

執行結果：

 構造過程如下圖加粗黑線：