/in/foo.cc: In function 'int main()':
/in/foo.cc:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<a.size();i++)
               ~^~~~~~~~~
/in/foo.cc:23:23: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if(!flag1[a[i]-'A']&&!flag2[b[i]-'A']||(m[a[i]]=b[i]))
       ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/in/foo.cc:42:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<c.size();i++)
              ~^~~~~~~~~