View Compilation Error

0_0_39424377_4157.cpp: In function 'int main()':
0_0_39424377_4157.cpp:20:25: error: 'memset' was not declared in this scope
   20 |                         memset(isprime,true,sizeof(isprime));
      |                         ^~~~~~
0_0_39424377_4157.cpp:2:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    1 | #include<stdio.h>
  +++ |+#include <cstring>
    2 | int n;