此代码检查链接列表是否为回文。
当我比较列表中的两个大于127的值时,它将返回该值始终不相等,例如运行[1,128,100,100,128,1],该代码将返回128!= 128,除非我在if语句中将它们强制转换为int。
我只是好奇为什么会这样。这是我的代码:
while(firstHalf != null && secondHalf != null)
{
//COMPARISON ONLY WORKS WHEN CASTED TO AN INT
if(((int)firstHalf.value) != ((int)secondHalf.value))
{
return false;
}
firstHalf = firstHalf.next;
secondHalf = secondHalf.next;
}
整个方法:
// Definition for singly-linked list:
// class ListNode<T> {
// ListNode(T x) {
// value = x;
// }
// T value;
// ListNode<T> next;
// }
//
boolean isListPalindrome(ListNode<Integer> l) {
if(l == null)
return true;
ListNode fastPnter = l;
ListNode slowPnter = l;
ListNode slowPnterPrev = l;
//find mid point
while(fastPnter != null && fastPnter.next !=null)
{
fastPnter = fastPnter.next.next;
slowPnterPrev = slowPnter;
slowPnter = slowPnter.next;
}
//odd case
if(fastPnter != null)
{
slowPnterPrev = slowPnter;
slowPnter = slowPnter.next;
}
//reverse second half
slowPnterPrev.next = null;
ListNode midNode = reverse(slowPnter);
//check halves
ListNode firstHalf = l;
ListNode secondHalf = midNode;
while(firstHalf != null && secondHalf != null)
{
//COMPARISON ONLY WORKS WHEN CASTED TO AN INT
if(((int)firstHalf.value) != ((int)secondHalf.value))
{
return false;
}
firstHalf = firstHalf.next;
secondHalf = secondHalf.next;
}
return true;
}
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