View Compilation Error

0_0_13956903_5732.cpp:31:11: error: '::main' must return 'int'
 void main()
           ^
0_0_13956903_5732.cpp: In function 'int main()':
0_0_13956903_5732.cpp:38:29: error: 'memset' was not declared in this scope
         memset(b,0,sizeof(b));
                             ^