/in/foo.cc: In function 'int main()':
/in/foo.cc:15:8: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  cin>>s+1;
       ~^~
/in/foo.cc:19:17: warning: statement has no effect [-Wunused-value]
   last[s[i]-'a']==i;
   ~~~~~~~~~~~~~~^~~
/in/foo.cc:23:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   cin>>p+1;
        ~^~