foo.cc: In function 'void dfs(int)':
foo.cc:82:10: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(c[x]=0) {c[x]=1;dfs(x+1);c[x]=0;}
      ~~~~^~
foo.cc:86:1: error: a function-definition is not allowed here before '{' token
 {
 ^
foo.cc:103:1: error: expected '}' at end of input
 }
 ^