View Compilation Error

0_0_16020507_14752.cpp: In function 'int main()':
0_0_16020507_14752.cpp:18:27: error: 'memset' was not declared in this scope
   memset(pre,0,sizeof(pre));
                           ^
0_0_16020507_14752.cpp: At global scope:
0_0_16020507_14752.cpp:37:3: error: expected unqualified-id before '<' token
 } </div><div style="FONT-FAMILY: Courier New,Courier,monospace"> </div><div style="FONT-FAMILY: Courier New,Courier,monospace"> </div><div style="FONT-FAMILY: Courier New,Courier,monospace"> </div><div style="FONT-FAMILY: Courier New,Courier,monospace"> </div>
   ^