View Compilation Error

0_0_37443533_16420.cpp: In function 'int slove(int)':
0_0_37443533_16420.cpp:28:23: error: 'memset' was not declared in this scope
  memset(x,-1,sizeof(x));
                       ^
0_0_37443533_16420.cpp: In function 'int main()':
0_0_37443533_16420.cpp:52:23: error: 'memset' was not declared in this scope
   memset(g,0,sizeof(g));
                       ^