View Compilation Error

0_0_29005318_30556.cpp: In function 'int bfs()':
0_0_29005318_30556.cpp:28:7: error: 'i' was not declared in this scope
   for(i=0;i<8;i++)
       ^
0_0_29005318_30556.cpp: In function 'int main()':
0_0_29005318_30556.cpp:47:29: error: 'memset' was not declared in this scope
   memset(flag,0,sizeof(flag));
                             ^