View Compilation Error

0_0_22351602_21336.cpp: In function 'int main()':
0_0_22351602_21336.cpp:55:27: error: 'memset' was not declared in this scope
   memset(vis,0,sizeof(vis));
                           ^
0_0_22351602_21336.cpp:58:7: error: 'i' was not declared in this scope
   for(i = 0; i < m;i++)
       ^