图论----最小生成树--（Prim算法）

C.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+const int MAXN = 101;
+int a[MAXN][MAXN];
+int dis[MAXN];//每个点到源点的距离
+int book[MAXN];//每个点是否加入到最小生成树中
+int n;
+int Prim(){
+    for(int i = 1; i <= n; i++){
+        dis[i] = INT_MAX;
+    }
+    for(int i = 1; i <= n; i++){
+        book[i] = 0;
+    }
+    dis[1] = 0;
+    book[1] = 1;
+    for(int i = 1; i < n; i++){
+        int u=1, MIN = INT_MAX;//寻找离最小生成树距离最短的点
+        for(int j = 2; j <= n; j++){
+            if(book[j] == 0 && dis[j] < MIN){
+                MIN = dis[j];
+                u = j;
+            }
+        }
+        book[u] = 1;
+        for(int j = 1; j <= n; j++){
+            if(book[j] == 0 && dis[j] > a[u][j]){
+                dis[j] = a[u][j];
+            }
+        }
+    }
+    int sum = accumulate(dis+1, dis+n+1,0);
+    return sum;
+}
+int main(){
+//    ifstream cin("input.txt");
+//    ofstream cout("output.txt");
+    while(cin >> n ){
+        if(n == 0)break;
+        for(int i = 1; i <= n; i++){
+            for(int j = 1; j <= n; j++){
+                a[i][j] = 0;
+            }
+        }
+        for(int i = 1; i <= n * ( n - 1) / 2; i++){
+            int x, y, z;
+            cin >> x >> y >> z;
+            a[x][y] = a[y][x] = z;
+        }
+        int sum = Prim();
+        cout << sum << endl;
+    }
+}