View Compilation Error

0_0_21032097_27846.cpp: In function 'void Dijkstra()':
0_0_21032097_27846.cpp:19:34: error: 'memset' was not declared in this scope
     memset(dist,0x7f,sizeof(dist));  
                                  ^
0_0_21032097_27846.cpp: In function 'int main()':
0_0_21032097_27846.cpp:62:36: error: 'memset' was not declared in this scope
         memset(map,0x7f,sizeof(map));  
                                    ^