foo.cpp: In function 'int main()':
foo.cpp:13:16: error: expected primary-expression before '?' token
             if(?s[i]>s[j]?&&?f[j]+1>f[i]?) f[i]=f[j]+1;
                ^
foo.cpp:13:29: error: expected identifier before '?' token
             if(?s[i]>s[j]?&&?f[j]+1>f[i]?) f[i]=f[j]+1;
                             ^
foo.cpp:13:42: error: expected primary-expression before ')' token
             if(?s[i]>s[j]?&&?f[j]+1>f[i]?) f[i]=f[j]+1;
                                          ^
foo.cpp:13:42: error: expected ':' before ')' token
foo.cpp:13:42: error: expected primary-expression before ')' token
foo.cpp:13:42: error: expected ':' before ')' token
foo.cpp:13:42: error: expected primary-expression before ')' token
foo.cpp:13:42: error: expected ':' before ')' token
foo.cpp:13:42: error: expected primary-expression before ')' token
foo.cpp:13:42: error: expected ':' before ')' token
foo.cpp:13:42: error: expected primary-expression before ')' token