猜数字（Bulls and Cows）游戏

// secret 秘密  guess 猜测
function get(secret, guess) {
  // 因为都是数字 建一个字典树 最多10个
  const trie = {};
  for (let i = 0; i < secret.length; i += 1) {
    trie[secret[i]] = 0
  }
  let bulls = 0;
  let cows = 0;
  for (let i = 0; i < guess.length; i += 1) {
    if (secret[i] === guess[i]) {
      // 公牛
      bulls += 1;
    } else if (trie[guess[i]] === 0) {
      // 奶牛
      trie[guess[i]] = 1;
    }
  }
  for (let i = 0; i <= 9; i += 1) {
    cows += trie[i] || 0
  }
  return `${bulls}A${cows}B`
}

get('1807', '7810') // 1A3B
get('1123', '0111') // 1A1B
get('1234', '4321') // 0A4B
get('111116', '100001') // 1A1B

var getHint = function (secret, guess) {
  var bull = 0;
  var cow = 0;
  // 储存
  var skeep = [];
  var gkeep = [];

  for (var i in guess) {
    if (secret[i] == guess[i]) {
      bull++;
    } else {
      skeep.push(secret[i]);
      gkeep.push(guess[i])
    }
  }

  for (var j in gkeep) {
    var findIndex = skeep.indexOf(gkeep[j]);
    if (findIndex != -1) {
      cow++;
      skeep[findIndex] = null;
    }
  }

  return bull + "A" + cow + 'B'
}