View Compilation Error

0_0_14580345_20967.cpp: In function 'void solve()':
0_0_14580345_20967.cpp:5:36: error: 'memset' was not declared in this scope
 #define clr(a) memset(a,0,sizeof(a))
                                    ^
0_0_14580345_20967.cpp:16:2: note: in expansion of macro 'clr'
  clr(rst);
  ^