气泡排序不排序 - IntDoublePair

Question

我已经实施气泡排序为了排序IntDoublePair。例如：

[1 0.5] 
[1 0.8] 
[1 0.67] 

排序为：

[1 0.5] 
[1 0.67] 
[1 0.8] 

当我执行的代码，它给我的数据不会按排序顺序。我很困惑，我哪里错了。我需要一些帮助。

private ArrayList<IntDoubleTextPair> sortCollection(ArrayList<IntDoubleTextPair> collection) 
    { 
     for (int current = 0; current < collection.size(); current++) 
     { 
      for (int next = 1; next < collection.size(); next++) 
      { 
       if (collection.get(current).getFirst().get() >= collection.get(next).getFirst().get()) 
       { 
        if (collection.get(current).getSecond().get() > collection.get(next).getSecond().get()) 
        { 
         temp = collection.get(next); 

         collection.set(next, collection.get(current)); 
         collection.set(current, temp); 
        } 
       } 
} 
} 
return collection; 
} 

Answer 1

我想你可能有一些错误的逻辑：

if (collection.get(current).getFirst().get() >= collection.get(next).getFirst().get()) 
    { 
     if (collection.get(current).getSecond().get() > collection.get(next).getSecond().get()) 
     { 
      temp = collection.get(next); 
      collection.set(next, collection.get(current)); 
      collection.set(current, temp); 
     } 
    } 

与这两个嵌套的if语句，交换机将不会在这个例子中发生，但它需要：

[2 .1] 
[1 .9] 

，因为即使第一个if语句的结果为true，第二个if语句也会失败，因为它仅查找第二个数字。也许这会更好：

if (collection.get(current).getFirst().get() >= collection.get(next).getFirst().get()) 
    { 
     if (collection.get(current).getFirst().get() == collection.get(next).getFirst().get()) 
     { 
      if (collection.get(current).getSecond().get() > collection.get(next).getSecond().get()) 
      { 
      temp = collection.get(next); 

      collection.set(next, collection.get(current)); 
      collection.set(current, temp); 
      } 
     } 

     else 
     { 
      temp = collection.get(next); 

      collection.set(next, collection.get(current)); 
      collection.set(current, temp); 
     } 
    } 

快乐编码！如果您有任何问题，请留下评论。

Answer 2

我认为这种排序应该至少对你传递的数组起作用（尽管嵌套的条件有问题），但是当你在交换操作中传递引用temp时可能会有问题，所以尝试创建一个临时对象，而不是通过参考传递值：

private ArrayList<IntDoubleTextPair> sortCollection(ArrayList<IntDoubleTextPair> collection) 
    { 
     for (int current = 0; current < collection.size(); current++) 
     { 
      for (int next = 1; next < collection.size(); next++) 
      { 
       if (collection.get(current).getFirst().get() >= collection.get(next).getFirst().get()) 
       { 

        if (collection.get(current).getSecond().get() > collection.get(next).getSecond().get()) 
        { 
         IntDoubleTextPair temp= new IntDoubleTextPair(); 
         temp.getFirst() = collection.get(next).getFirst(); 
         temp.getSecond() = collection.get(next).getSecond(); 

         collection.set(next, collection.get(current)); 
         collection.set(current, temp); 
        } 
        else if(collection.get(current).getFirst().get() != collection.get(next).getFirst().get()){ 
         IntDoubleTextPair temp= new IntDoubleTextPair(); 
         temp.getFirst() = collection.get(next).getFirst(); 
         temp.getSecond() = collection.get(next).getSecond(); 

         collection.set(next, collection.get(current)); 
         collection.set(current, temp); 

         } 
       } 
} 
} 
return collection; 
}