View Compilation Error

0_0_35297466_9637.cpp: In function 'int f_gt(vec&, int, int)':
0_0_35297466_9637.cpp:20:35: error: 'memset' was not declared in this scope
 #define ms(a) memset(a,0,sizeof(a))
                                   ^
0_0_35297466_9637.cpp:35:5: note: in expansion of macro 'ms'
     ms(dp),ms(ma);
     ^