View Compilation Error

0_0_21110574_29988.cpp:6:11: error: '::main' must return 'int'
 void main()
           ^
0_0_21110574_29988.cpp: In function 'int main()':
0_0_21110574_29988.cpp:12:35: error: 'memset' was not declared in this scope
         memset(str, 0, sizeof(str));
                                   ^