View Compilation Error

0_0_32104812_9701.cpp: In function 'int main()':
0_0_32104812_9701.cpp:14:23: error: 'memset' was not declared in this scope
   memset(s,0,sizeof(s));
                       ^
0_0_32104812_9701.cpp:36:14: error: 'mid' was not declared in this scope
     ans=cost[mid];
              ^
0_0_32104812_9701.cpp:38:11: error: 'mid' was not declared in this scope
     ans=p[mid-1]*q;
           ^