View Compilation Error

0_0_20264572_25113.cpp: In function 'int main()':
0_0_20264572_25113.cpp:9:25: error: 'memset' was not declared in this scope
   memset(p, 0, sizeof(p));
                         ^
0_0_20264572_25113.cpp:11:19: error: 'strlen' was not declared in this scope
   int n = strlen(s);
                   ^