View Compilation Error

0_0_20120782_8054.cpp: In function 'int H(int)':
0_0_20120782_8054.cpp:36:33: error: 'memset' was not declared in this scope
     memset(color,0,sizeof(color));
                                 ^
0_0_20120782_8054.cpp: In function 'int main()':
0_0_20120782_8054.cpp:67:34: error: 'memset' was not declared in this scope
         memset(vis,-1,sizeof(vis));
                                  ^