View Compilation Error

0_0_18252368_798.cpp: In function 'int main()':
0_0_18252368_798.cpp:11:42: error: 'memset' was not declared in this scope
 #define MEM(x,i) memset((x),(i),sizeof(x))
                                          ^
0_0_18252368_798.cpp:25:3: note: in expansion of macro 'MEM'
   MEM(td,0);
   ^