package com.nxz.blog.otherTest;public class TestLeetCode {public static void main(String[] args) {TestLeetCode t = new TestLeetCode();ListNode l1 = new ListNode(2);ListNode l2 = new ListNode(4);ListNode l3 = new ListNode(3);ListNode r1 = new ListNode(5);ListNode r2 = new ListNode(6);ListNode r3 = new ListNode(4);l1.next = l2;l2.next = l3;r1.next = r2;r2.next = r3;ListNode listNode = t.addTwoNumbers(l1, r1);do {System.out.println(listNode.val);} while ((listNode = listNode.next )!= null);}/*** 循环 l1 和 l2 两个listnode，当l1 或 l2 不为null的时候，将两个数相加，大于10时进行处理（保存进一位），否则视为0和另一个值相加** @param l1* @param l2* @return*/public ListNode addTwoNumbers(ListNode l1, ListNode l2) {　　　　　//哑结点，最终返回的节点就是该节点的下一个节点ListNode dummyHead = new ListNode(-1);//暂存变量ListNode p = l1, q = l2, curr = dummyHead;//大于10时的暂存值int carry = 0;//当p或q不为null是，将值相加，此时需要处理，其中一个为null的情况while (p != null || q != null) {//只要p或q为nul时，将val值默认为0，和另一个值相加int x = p != null ? p.val : 0;int y = q != null ? q.val : 0;int sum = carry + x + y;//重新设置进一变量carry = sum / 10;curr.next = new ListNode(sum % 10);//重新设置当前节点，p，q节点，以便再一次循环curr = curr.next;if (p != null) {p = p.next;}if (q != null) {q = q.next;}}//最后处理最高为的carry的值if (carry > 0) {curr.next = new ListNode(carry);}return dummyHead.next;}public static class ListNode {int val;ListNode next;ListNode(int x) {val = x;}}
}

package com.nxz.blog.otherTest;import java.util.Stack;public class TestLeetCode {public static void main(String[] args) {TestLeetCode t = new TestLeetCode();ListNode l1 = new ListNode(2);ListNode l2 = new ListNode(4);ListNode l3 = new ListNode(3);ListNode r1 = new ListNode(5);ListNode r2 = new ListNode(6);ListNode r3 = new ListNode(4);l1.next = l2;l2.next = l3;r1.next = r2;r2.next = r3;ListNode listNode = t.addTwoNumbers(l1, r1);do {System.out.println(listNode.val);} while ((listNode = listNode.next) != null);}/*** 利用栈这种数据结构（先进后出），这样就可以将正序的节点转换为倒叙的节点了，这样依次从两个栈中取出值（顺序就是个、十、百。。。）* 这样就转换为之前的那种方式了** @param l1* @param l2* @return*/public ListNode addTwoNumbers(ListNode l1, ListNode l2) {Stack<ListNode> stack1 = new Stack<>();Stack<ListNode> stack2 = new Stack<>();ListNode dummyHead = new ListNode(-1);ListNode p = l1, q = l2, head = dummyHead;while (p != null) {stack1.add(p);p = p.next;}while (q != null) {stack2.add(q);q = q.next;}p = stack1.pop();q = stack2.pop();int carry = 0;while (p != null || q != null) {int x = p != null ? p.val : 0;int y = q != null ? q.val : 0;int sum = carry + x + y;carry = sum / 10;ListNode last = head.next;head.next = new ListNode(sum % 10);head.next.next = last;p = stack1.isEmpty() ? null : stack1.pop();q = stack2.isEmpty() ? null : stack2.pop();}if (carry > 0) {ListNode last = head.next;head.next = new ListNode(carry);head.next.next = last;}return dummyHead.next;}public static class ListNode {int val;ListNode next;ListNode(int x) {val = x;}}
}