View Compilation Error

0_0_21400428_10382.cpp: In function 'void Init()':
0_0_21400428_10382.cpp:25:29: error: 'memset' was not declared in this scope
     memset(vis,0,sizeof(vis));
                             ^
0_0_21400428_10382.cpp: In function 'int main(int, const char**)':
0_0_21400428_10382.cpp:63:29: error: 'memset' was not declared in this scope
         memset(g,0,sizeof(g));
                             ^