/in/foo.cc: In function 'int f(std::__cxx11::string)':
/in/foo.cc:42:17: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int ans='E'-j;//"E"是翻译成的明文，求偏移量用"E"-某出现最多字母 
                 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:42:17: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int ans='E'-j;//"E"是翻译成的明文，求偏移量用"E"-某出现最多字母 
                 ^
/in/foo.cc:33:16: note: 'j' was declared here
     int maxn=0,j;
                ^