View Compilation Error

0_0_34076829_22637.cpp: In function 'void init()':
0_0_34076829_22637.cpp:31:6: error: 'vis' was not declared in this scope
  mst(vis);
      ^
0_0_34076829_22637.cpp:7:23: note: in definition of macro 'mst'
 #define mst(x) memset(x, 0 ,sizeof x)
                       ^