Minimum-genetic-mutation

The topic is still very good, providing a new direction of thinking.

Details, the beginning of my judgment conditions with the dict, not very good, then debug good.

In addition, note the method of initializing Set with an array:set<string> dict = new HashSet (arrays.aslist (bank));

and set<string> a = new hash<> (); The reason that the front <> inside of the string is extracted is directly a string, followed by <> refers to the acceptance of various types. The non-additive <> indicates that the type is not differentiated and should be equivalent to <>.

Https//leetcode.com/problems/minimum-genetic-mutation///This method is particularly good// Https://discuss.leetcode.com/topic/63959/c-two-end-bfs-solution-exactly-same-as-127-word-ladder//mentioned withhttps://leetcode.com/problems/word-ladder/127 Word Ladder The exact same question.//Look, yes, I did. Public classSolution {//This topic uses both sides of the BFs method, and then through the substitution of strings, to reduce the priority//before another topic Word ladder inside, with one end to the other end of the//Now this is a bit more subtle, because finding results from a set is more efficient than traversing the contents of a set.     Public intminmutation (string start, String end, string[] bank) {Set<String> dict =NewHashSet (arrays.aslist (bank)); if(!dict.contains (end)) {            return-1; } Set<String> Lessset =NewHashSet (); Set<String> Moreset =NewHashSet (); Char[] chlist = {' A ', ' C ', ' G ', ' T '};        Lessset.add (start);        Moreset.add (end); intStep = 0;  while(true) {            //wrong:if dict is empty, no need to check more//Right:check Lessset            if(Lessset.isempty ()) {return-1; }            if(Moreset.size () <lessset.size ()) {Set<String> tmp =Lessset; Lessset=Moreset; Moreset=tmp; }            //Printset (Lessset, Moreset, dict);Step++; Iterator<String> iter =Lessset.iterator (); Set<String> Newset =NewHashSet ();  while(Iter.hasnext ()) {String str=Iter.next ();  for(inti=0; I<str.length (); i++) {StringBuilder sb=NewStringBuilder (str);  for(intj=0; j<4; J + +) {                        if(Str.charat (i) = =Chlist[j]) {                            Continue;                        } sb.setcharat (I, chlist[j]); if(Moreset.contains (sb.tostring ())) {returnstep; }                        if(Dict.contains (sb.tostring ())) {Dict.remove (sb.tostring ());                        Newset.add (Sb.tostring ()); } }}} Lessset=Newset; }    }    Private voidPrintset (set<string> lessset, set<string> Moreset, set<string>dict) {System.out.printf ("Here is Lessset:"); Iterator<String> iter =Lessset.iterator ();  while(Iter.hasnext ()) {System.out.printf ("%s,", Iter.next ());        } System.out.println (); System.out.printf ("Here is Moreset:"); ITER=Moreset.iterator ();  while(Iter.hasnext ()) {System.out.printf ("%s,", Iter.next ());        } System.out.println (); System.out.printf ("Here is dict:"); ITER=Dict.iterator ();  while(Iter.hasnext ()) {System.out.printf ("%s,", Iter.next ());        } System.out.println (); System.out.println ("################"); }}

Minimum-genetic-mutation