Title: "The Beauty of programming" P223
String sub_string (const string &s, const int Begin,const int end) {if (Begin > End) return "", Return S.substr (Begin, end);} int Strings_distance (string s1, string s2) {if (S1.size () < S2.size ()) {string tmp = S1;S1 = S2;S2 = tmp;} if (s2.size () = = 0) return s1.size (); int i;for (i = 0; i < s2.size (); i++) {if (S1[i]! = S2[i]) break; if (i = = S2.size ()) return s1.size ()-s2.size (), if (i! = 0) {S1 = sub_string (S1, I, S1.size ()-1); s2 = sub_string (s2, I, S 2.size ()-1); return strings_distance (S1, S2);} int r1 = strings_distance (sub_string (S1, 1, S1.size ()-1), s2); int r2 = strings_distance (sub_string (S2, 1, S2.size ()-1) , s1); int r3 = Strings_distance (Sub_string (S1, 1, S1.size ()-1), sub_string (S2, 1, S2.size ()-1)); r1 = r1>r2? R2:R1;R1 = r1 > R3? R3:r1;return r1 + 1;}
"Hard" "array" calculates the similarity of characters