View Compilation Error

0_0_19631869_10282.cpp: In function 'int main()':
0_0_19631869_10282.cpp:16:35: error: 'memset' was not declared in this scope
         memset(mark,0,sizeof(mark));
                                   ^
0_0_19631869_10282.cpp:29:21: error: expected primary-expression before ';' token
     for (int i=1;i<=;i++){
                     ^