View Compilation Error

0_0_34933906_32013.cpp: In function 'void init()':
0_0_34933906_32013.cpp:15:26: error: 'memset' was not declared in this scope
  memset(sg, -1, sizeof sg);
                          ^
0_0_34933906_32013.cpp: In function 'int getsg(int)':
0_0_34933906_32013.cpp:20:27: error: 'memset' was not declared in this scope
  memset(vis, 0, sizeof vis);
                           ^