View Compilation Error

0_0_21255758_15670.cpp:2:15: error: expected constructor, destructor, or type conversion before '(' token
         memset(head,-1,sizeof(head));
               ^
0_0_21255758_15670.cpp:3:15: error: expected constructor, destructor, or type conversion before '(' token
         memset(mark,0,sizeof(mark));
               ^
0_0_21255758_15670.cpp:4:9: error: 'cnt' does not name a type
         cnt=0;
         ^
0_0_21255758_15670.cpp:5:9: error: 'flag' does not name a type
         flag=1;
         ^
0_0_21255758_15670.cpp:6:14: error: expected constructor, destructor, or type conversion before '(' token
         scanf("%d%d",&n,&m);
              ^
0_0_21255758_15670.cpp:7:9: error: expected unqualified-id before 'for'
         for(int i=0;i<m;i++)
         ^
0_0_21255758_15670.cpp:7:21: error: 'i' does not name a type
         for(int i=0;i<m;i++)
                     ^
0_0_21255758_15670.cpp:7:25: error: 'i' does not name a type
         for(int i=0;i<m;i++)
                         ^