View Compilation Error

0_0_28632760_5479.cpp: In function 'int cal_h()':
0_0_28632760_5479.cpp:38:33: error: 'memset' was not declared in this scope
     memset(vis,false,sizeof(vis));
                                 ^
0_0_28632760_5479.cpp: In function 'bool IDA(int, int)':
0_0_28632760_5479.cpp:106:59: error: 'memset' was not declared in this scope
     memset(available_colors,false,sizeof(available_colors));
                                                           ^