View Compilation Error

0_0_31936335_29690.cpp:5:11: error: '::main' must return 'int'
 void main(){
           ^
0_0_31936335_29690.cpp: In function 'int main()':
0_0_31936335_29690.cpp:15:29: error: 'memset' was not declared in this scope
         memset(s,0,sizeof(s));
                             ^