View Compilation Error

0_0_25840555_30974.cpp: In function 'void dfs(int)':
0_0_25840555_30974.cpp:27:9: error: 'i' was not declared in this scope
     for(i=1;i<=adj[root][0];i++)  
         ^
0_0_25840555_30974.cpp: In function 'int main()':
0_0_25840555_30974.cpp:50:37: error: 'memset' was not declared in this scope
         memset(vis,false,sizeof(vis));  
                                     ^
0_0_25840555_30974.cpp:55:13: error: 'i' was not declared in this scope
         for(i=1;i<N;i++)   
             ^