View Compilation Error

0_0_22146767_24612.cpp: In function 'void init()':
0_0_22146767_24612.cpp:27:32: error: 'memset' was not declared in this scope
     memset(heap,-1,sizeof(heap));
                                ^
0_0_22146767_24612.cpp: In function 'void bfs(int)':
0_0_22146767_24612.cpp:30:34: error: 'memset' was not declared in this scope
     memset(level,-1,sizeof(level));
                                  ^