View Compilation Error

0_0_21441553_5194.cpp: In function 'int dfs(int, int)':
0_0_21441553_5194.cpp:18:5: error: return-statement with no value, in function returning 'int' [-fpermissive]
     return ;
     ^
0_0_21441553_5194.cpp: In function 'int main()':
0_0_21441553_5194.cpp:27:33: error: 'memset' was not declared in this scope
         memset(vis,0,sizeof(vis));
                                 ^