View Compilation Error

0_0_15471983_8952.cpp: In function 'void check()':
0_0_15471983_8952.cpp:28:3: error: 'ans' was not declared in this scope
   ans++;
   ^
0_0_15471983_8952.cpp:31:3: error: 'ans' was not declared in this scope
   ans++;
   ^
0_0_15471983_8952.cpp:34:3: error: 'ans' was not declared in this scope
   ans++;
   ^
0_0_15471983_8952.cpp:37:3: error: 'ans' was not declared in this scope
   ans++;
   ^
0_0_15471983_8952.cpp: In function 'int dfs(int, int)':
0_0_15471983_8952.cpp:42:2: error: expected ',' or ';' before 'if'
  if (k == n) {
  ^