Update 最小生成树.cpp

Author: coder-Zzx

第四章/最小生成树.cpp

@@ -1,10 +1,87 @@
-#include<iostream>
+#include <iostream>
 using namespace std;
-/* coded by zzx */
-/* 这题和上一题一样只有一个用例并且还就是示例，所以直接偷鸡 */
+#define MAX 100
+/* coded by zzx 4.3 由于oj系统无法登录故没有针对oj上的测试用例测试，只是自己测试了一下，输入输出格式等都需要再更改 */
+
+class Graph
+{
+public:
+    int G[6][6];
+    Graph(int num);
+    int prim(int num);
+};
+
+Graph::Graph(int num)
+{
+    for (int i = 0; i < num; i++)
+    {
+        for (int j = 0; j < num; j++)
+        {
+            this->G[i][j] = MAX;
+        }
+    }
+    int n;
+    cin >> n;
+    int x, y, weight;
+    for (int i = 0; i < n; i++)
+    {
+        cin >> x >> y >> weight;
+        this->G[x][y] = weight;
+        this->G[y][x] = weight;
+    }
+}
+
+int Graph::prim(int num)
+{
+    int sum = 0,
+        min = MAX,
+        minid = 0;
+    // int g[num][num] = this->G;
+    int lowcost[num]; // lowcost[i]即表示起点到第i个点的最短路径
+    int mst[num];     // mst[i]表示最小生成树中第i个结点的前驱结点
+    for (int i = 1; i < num; i++)
+    {
+        //将第一个结点作为最小生成树的根节点
+        lowcost[i] = this->G[0][i];
+        mst[i] = 0;
+    }
+    mst[0] = 0;
+    for (int i = 1; i < num; i++)
+    {
+        /* 找出n-1个点，所以从1循环到n-1 *
+         * 不断循环找出每个点的最短路径   */
+        min = MAX;
+        minid = 0;
+        for (int i = 1; i < num; i++)
+        {
+            if (lowcost[i] < min && lowcost[i] != 0)
+            {
+
+                min = lowcost[i];
+                minid = i;
+            }
+        }
+        sum += min;
+        lowcost[minid] = 0; //找到了最小的结点，将其放入最小生成树中
+        for (int i = 1; i < num; i++)
+        {
+            //
+            if (this->G[minid][i] < lowcost[i])
+            {
+                lowcost[i] = this->G[minid][i];
+                mst[i] = minid;
+            }
+        }
+    }
+    return sum;
+}
 
 int main()
 {
-    cout<<19；
+    int num;
+    cin >> num;
+    Graph *g = new Graph(num);
+    int w = g->prim(num);
+    cout << "最小生成树的权值和为" << w << endl;
     return 0;
 }