diff --git a/HDOJ/1879.cpp b/HDOJ/1879.cpp
new file mode 100644
index 0000000..6d0c10b
--- /dev/null
+++ b/HDOJ/1879.cpp
@@ -0,0 +1,105 @@
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <algorithm>
+#include <vector>
+#include <queue>
+using namespace std;
+
+#define MAXN 105
+int father[MAXN];
+int noderank[MAXN];
+
+void init()
+{
+    for(int i=0;i<MAXN;i++)
+    {
+        father[i]=i;
+        noderank[i]=0;
+    }
+}
+
+int findfather(int node)
+{
+    if(father[node]!=node)
+    {
+        father[node]=findfather(father[node]);
+    }
+    return father[node];
+}
+
+void UNION(int a,int b)
+{
+    int fa=findfather(a);
+    int fb=findfather(b);
+    if(fa==fb)
+    {
+        return;
+    }
+    if(noderank[fa]>noderank[fb])
+    {
+        father[fb]=fa;
+    }
+    else
+    {
+        father[fa]=fb;
+        if(noderank[fa]==noderank[fb])
+        {
+            noderank[fb]++;
+        }
+    }
+}
+
+struct pack
+{
+    int a,b,v;
+};
+#define MAXM 5000
+pack pk[MAXM];
+
+bool cmp(const pack& a,const pack& b)
+{
+    return a.v<b.v;
+}
+
+int main()
+{
+    int N;
+    while(scanf("%d",&N)==1&&N!=0)
+    {
+        init();
+        int cnt=0;
+        int a,b,c,d;
+        int M=(N-1)*N/2;
+        for(int i=0;i<M;i++)
+        {
+            /// Start End Value IsBuilt
+            scanf("%d %d %d %d",&a,&b,&c,&d);
+            if(d)
+            {
+                UNION(a,b);
+            }
+            else
+            {
+                pk[cnt].a=a;
+                pk[cnt].b=b;
+                pk[cnt].v=c;
+                ++cnt;
+            }
+        }
+        sort(pk,pk+cnt,cmp);
+        int ans=0;
+        for(int i=0;i<cnt;i++)
+        {
+            int fa=findfather(pk[i].a);
+            int fb=findfather(pk[i].b);
+            if(fa!=fb)
+            {
+                UNION(fa,fb);
+                ans+=pk[i].v;
+            }
+        }
+        printf("%d\n",ans);
+    }
+    return 0;
+}