View Compilation Error

0_0_32197093_7278.cpp: In function 'void clear()':
0_0_32197093_7278.cpp:7:14: error: 'len' was not declared in this scope
  for(int i=n-len+1; i<=n; i++) rec[i]=0;
              ^
0_0_32197093_7278.cpp: In function 'bool check(int)':
0_0_32197093_7278.cpp:21:25: error: too many arguments to function 'void clear()'
   if(have>=p) {clear(len);return 1;}
                         ^
0_0_32197093_7278.cpp:6:6: note: declared here
 void clear() {
      ^
0_0_32197093_7278.cpp:23:11: error: too many arguments to function 'void clear()'
  clear(len);
           ^
0_0_32197093_7278.cpp:6:6: note: declared here
 void clear() {
      ^