View Compilation Error

0_0_29767219_22943.cpp: In function 'int BFS(int, int)':
0_0_29767219_22943.cpp:27:34: error: 'memset' was not declared in this scope
         memset(pre,-1,sizeof(pre));
                                  ^
0_0_29767219_22943.cpp: In function 'int main()':
0_0_29767219_22943.cpp:77:33: error: 'memset' was not declared in this scope
         memset(map,0,sizeof(map));
                                 ^