【当前无排名】挑战leetcode进入前1w名

李恒道

https://leetcode.cn/problems/happy-number/submissions/576209580/?envType=study-plan-v2&envId=top-interview-150
缓存秒了

var isHappy = function (n) {
  const cache = new Map();
  while (true) {
    if (cache.has(n)) {
      return false;
    }
    cache.set(n, true);
    let newN = 0;
    while (n != 0) {
      newN += (n % 10) * (n % 10);
      n = parseInt(n / 10);
    }
    n = newN;
    if(newN==1){
      break;
    }
  }
  return true
};

李恒道

https://leetcode.cn/problems/valid-sudoku/submissions/576211089/?envType=study-plan-v2&envId=top-interview-150
脑筋急转弯题

var isValidSudoku = function (board) {

  for (let index = 0; index < board.length; index++) {
    const hasNum = new Array(10).fill(false);
    for (let indey = 0; indey < board[0].length; indey++) {
      const char = board[index][indey];
      if (char !== ".") {
        if (hasNum[char]) {
          return false;
        }
        hasNum[char] = true;
      }
    }
  }
  //竖排
  for (let index = 0; index < board[0].length; index++) {
    const hasNum = new Array(10).fill(false);
    for (let indey = 0; indey < board.length; indey++) {
      const char = board[indey][index];
      if(char=='5'){
        debugger
      }
      if (char !== ".") {
        if (hasNum[char]) {
          return false;
        }
        hasNum[char] = true;
      }
    }
  }
  for (let x = 0; x < board[0].length / 3; x++) {
    for (let y = 0; y < board.length / 3; y++) {
      const hasNum = new Array(10).fill(false);
      for (let index = 0; index < 3; index++) {
        for (let indey = 0; indey < 3; indey++) {
          const char = board[x * 3 + index][y * 3 + indey];
          if (char !== ".") {
            if (hasNum[char]) {
              return false;
            }
            hasNum[char] = true;
          }
        }
      }
    }
  }
  return true;
};