Longest Common Prefix

[barretlee]

本题难度：★

写一个函数，找出一个字符串数组的最长共同前缀。例如：

给定 ['hi, barret', 'hi, skylar', 'hi, john']，输出 'hi, '

[barretlee]

function resolve(arr) {
  var commonPrefix = arr[0];
  for (var i = 1, len = arr.length; i < len; i++) {
    if (arr[i].length < commonPrefix.length) {
      commonPrefix = commonPrefix.slice(0, arr[i].length);
    }
    var count = commonPrefix.length;
    while (count--) {
      if (commonPrefix[count] !== arr[i][count]) {
        commonPrefix = commonPrefix.slice(0, count); 
      }
    }
    if (!commonPrefix.length) return '';
  }
  return commonPrefix;
}

var ret = resolve(['hi, barret', 'hi, skylar', 'hi, john']);
console.assert(ret === 'hi, ', ret);

[YabZhang]

def resolve(seq):
  """
    longest common prefix
  """
    if not seq:
        return ''
    
    result = list(seq[0])
    for item in seq:
        if len(item) < len(result):
            result = result[:len(item)]
        for i in range(len(result)):
            if result[i] != item[i]:
                break
        if i != len(result) - 1:
            result = result[:i]
    return ''.join(result)