- Unique Morse Code Words题目链接804. Unique Morse Code Words题目分析这个题目要求算出把给定数组中的字符串转换成摩尔斯码后，有多少个不同的摩尔斯码。思路第一步需要把字符串转换成摩尔斯码。$morse = [ “.-”,"-…","-.-.","-..",".","..-.","–.","….","..",".—","-.-",".-..","–", “-.”,"—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."];$replaced = [];foreach($words as $word){ $chars = str_split($word); $string = ‘’; foreach($chars as $char){ $string .= $morse[ord($char)-ord(‘a’)]; }}转换完成后存进数组内，再用array_unique函数排除。再count排除结果即可。最终代码<?phpclass Solution { function uniqueMorseRepresentations($words) { $morse = [".-","-…","-.-.","-..",".","..-.","–.","….","..",".—","-.-",".-..","–","-.","—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."]; $replaced = []; foreach($words as $word){ $chars = str_split($word); $string = ‘’; foreach($chars as $char){ $string .= $morse[ord($char)-ord(‘a’)]; } $replaced[] = $string; } return count(array_unique($replaced)); }}若觉得本文章对你有用，欢迎用爱发电资助。优化方案直接存为数组的键则可以省去用array_unique去重的步骤。