除去自我比较。。。

mooctest-site-server/src/main/java/cn/iselab/mooctest/site/web/logic/impl/SimilarityLogicImpl.java

@@ -40,7 +40,7 @@ public class SimilarityLogicImpl implements SimilarityLogic{
         }
         Long[] ids = (Long[])usersVector.keySet().toArray();
         for(int i=0; i<usersVector.size(); i++) {
-            for(int j = i; j<usersVector.size(); j++) {
+            for(int j = i+1; j<usersVector.size(); j++) {
                 long userId1 = ids[i];
                 long userId2 = ids[j];
                 double tempSimilarity = getSimilarity(usersVector.get(userId1), usersVector.get(userId2));