View Compilation Error

0_0_38573696_5191.cpp: In function 'void init()':
0_0_38573696_5191.cpp:26:5: error: 'memset' was not declared in this scope
     memset(head, -1, sizeof head);
     ^~~~~~
0_0_38573696_5191.cpp:26:5: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
0_0_38573696_5191.cpp:2:1:
+#include <cstring>
 #include<stdio.h>
0_0_38573696_5191.cpp:26:5:
     memset(head, -1, sizeof head);
     ^~~~~~