LeetCode & linked list bug All In One

add-two-numbers

https://leetcode.com/problems/add-two-numbers/
https://leetcode.cn/problems/add-two-numbers/

// 字符串相加 / 大数相加
const addStrings = function(num1, num2) {
  let res = '';
  let temp = 0;
  const arr1 = num1.split('');
  const arr2 = num2.split('');
  while (arr1.length || arr2.length || temp) {
    // `~~` double bitwise not 双非位运算, 字符串转换成整数
    temp += ~~arr1.pop() + ~~arr2.pop();
    // 字符串相加，要注意先后顺序
    res = (temp % 10) + res;
    // 进位
    temp = temp > 9 ? 1 : 0;
  }
  // console.log('res =', res, typeof res);
  return res === "0" ? res : res.replace(/^0+/, '');
}

~~ double bitwise not 双非位运算, 字符串转换成整数

let s = `3`;
// '3'

~s;
// -4

~~s;
// 3

+s;
// 3

shit test

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} l1
 * @param {ListNode} l2
 * @return {ListNode}
 */
var addTwoNumbers = function(l1, l2) {
  const log = console.log;
  function ListNode(val, next) {
    this.val = 0 || val;
    this.next = null || next;
  }
  log(`l1`, l1)
  log(`l2`, l2)
  const arr1 = [];
  const arr2 = [];
  while(l1) {
    arr1.push(l1.val);
    l1 = l1.next;
  }
  while(l2) {
    arr2.push(l2.val)
    l2 = l2.next;
  }
  const sum = parseInt(arr1.reverse().join(``)) + parseInt(arr2.reverse().join(``));
  // 807
  const arr = Array.from(sum + ``).reverse().map(i => parseInt(i));
  // [7, 0, 8]
  const LinkedList = (value) => {
    const node = new ListNode(value, ``);
    if(!head) {
      head = node;
    } else {
      let current = head;
      while(current.next) {
        current = current.next;
      }
      current.next = node;
    }
  };
  let head = null;
  for (let i = 0; i < arr.length; i++) {
    LinkedList(arr[i]);
  }
  log(`head`, head)
  return head;
  // return arr;
};

/* 

好垃圾的测试呀，为什么参数给的不是 ListNode, 而是 array！

答案没有毛病呀

l1 [2,4,3]
l2 [5,6,4]
head ListNode {
  val: 7,
  next: ListNode { val: 0, next: ListNode { val: 8, next: '' } }
}


 */

链表生成器


// singly-linked list
class ListNode {
  val: number
  next: ListNode | null
  constructor(val?: number, next?: ListNode | null) {
    this.val = (val===undefined ? 0 : val)
    this.next = (next===undefined ? null : next)
  }
  // add
  // remove
}

// 链表生成
const linkedListGenerator = (arr) => {
  let head;
  for (const item of arr) {
    const node = new ListNode(item);
    if(!head) {
      head = node;
    } else {
      let temp = head;
      // 关键：迭代 next
      while(temp.next) {
        temp = temp.next;
      }
      temp.next = node;
    }
  }
  return head;
}

大数相加

字符串相加，修复大数科学计数法的 bug ?

/*

[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1].join('')

'1000000000000000000000000000001'
[5,6,4].join('')
'564'
[5,6,4].reverse().join('')
'465'
[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1].reverse().join('')

'1000000000000000000000000000001'
parseInt('1000000000000000000000000000001');
1e+30
parseInt('1000000000000000000000000000001') +  parseInt('465')
1e+30
sum = parseInt('1000000000000000000000000000001') +  parseInt('465');

1e+30
`${sum}`.split('');
(5) ['1', 'e', '+', '3', '0']

科学计数法 ??? 字符串相加 ??? 进位

*/

https://leetcode.com/submissions/detail/661919117/

https://leetcode.com/problems/add-two-numbers/
https://leetcode.cn/problems/add-two-numbers/