diff --git a/bcj.cpp b/bcj.cpp
new file mode 100644
index 0000000..e589c3b
--- /dev/null
+++ b/bcj.cpp
@@ -0,0 +1,76 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+class Solution {
+public:
+    int minMalwareSpread(vector<vector<int>>& graph, vector<int>& initial) {
+        int n=graph.size();
+        vector<int> sz(n,1); //n号节点如果是祖先，他的孩子个数
+        vector<int> v_num(n,0);//n号节点如果是祖先，他的孩子中initial的个数
+        for (int i: initial){
+            v_num[i]=1;
+        }
+        //并查集核心模板代码
+        //并查集祖先数组定义
+        vector<int> pa(n);
+        //并查集祖先数组初始化
+        for (int i=0;i<n;i++) {
+            pa[i]=i;
+        }
+        //并查集查找祖先函数
+        function<int (int)> query = [&](int i){
+            if (pa[i]!=i)
+                pa[i]=query(pa[i]);
+            return pa[i];
+        };
+        //并查集合并祖先函数
+        auto link = [&](int i,int j){
+            int li=query(i);
+            int lj=query(j);
+            if (li != lj){
+                pa[li]=lj;
+                //其他附加操作
+                sz[lj]+=sz[li];
+                sz[li]=0;
+                v_num[lj]+=v_num[li];
+                v_num[li]=0;
+            }
+            return;
+        };
+        //
+        //建立并查集，合并祖先
+        for (int i=0;i<n;i++){
+            for (int j=0;j<n;j++){
+                if (graph[i][j]==1)
+                    link(i,j);
+            }
+        }
+        int res=n;
+        int res_multi=n;
+        int max_nodes=0;
+        bool have_one=false;
+        for (int i:initial){
+            int li=query(i);
+            if (v_num[li]==1){
+                if (sz[li]>max_nodes){
+                    res=i;
+                    max_nodes=sz[li];
+                }else if (sz[li]==max_nodes){
+                    res=min(res,i);
+                }
+                have_one=true;
+            } else {
+                res_multi=min(res_multi,i);
+            }
+        }
+        return have_one?res:res_multi;
+    }
+};
+int main()
+{
+    Solution sol;
+    vector<vector<int>> graph={{1,0,0},{0,1,0},{0,0,1}};
+    vector<int> initial={0,2};
+    cout << sol.minMalwareSpread(graph,initial) << endl;
+    return 0;
+}