Java-找出單鏈表的倒數第k結點

標籤：java   單鏈表   

/** * 兩個指標，一個先走k-1步，然後兩個同時向後移動，當提前走的指標移動到鏈表尾部時，落後的那個指標正好是要找的節點 * @param root * @param k * @return */public static ListNode findKthTotail(ListNode root,int k){if(root==null || k<=0){return null;}ListNode ahead = root;ListNode behind = root;for(int i=0; i<k-1; i++){if(ahead.getNext() != null){ahead = ahead.getNext();} else{return null;}}while(ahead.getNext() != null){ahead = ahead.getNext();behind = behind.getNext();}return behind;}

Java-找出單鏈表的倒數第k結點