javascript - 查找数组中重复字符的唯一索引

Question

我正在循环遍历一个字符串数组及其字符，以将它们的索引与另一个字符数组进行比较。该代码一直有效，直到字符串具有重复字符 - 然后它仅返回第一个(重复)字符的索引。例如:[“IAMDEFANDJKL”] 对于“A”和“D”，循环仅返回每次出现的第一个索引。

例如:[“abode”]返回[1,2,4,5]，然后在应用.length之后返回[4] - 所以[“IAMDEFANDJKL”]应该返回[4,5,6,10,11 ,12] 然后返回 [6](当前返回 [7]，因为“D”出现两次)

如何编辑代码以返回所有字符的唯一索引？

function solve() {  
  var alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 
                  'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 
                  'u', 'v', 'w', 'x', 'y', 'z'];
  var testArray = ["IAMDEFANDJKL","thedefgh","xyzDEFghijabc"];
  var countArray = [];

  for(var i = 0; i < testArray.length; i++) {
    var string = testArray[i];
    var newArray = [];

    for(var char = 0; char < string.length; char++) {
      var character = string.charAt(char);
      var characterIndex = string.indexOf(character);

      for(var alpha = 0; alpha < alphabet.length; alpha++) {
        var alphaString = alphabet[alpha];
        var alphaIndex = alphabet.indexOf(alphaString);
        var characterUpper = character.toUpperCase();
        var alphaStringUpper = alphaString.toUpperCase();

        if(characterIndex === alphaIndex && characterUpper === 
           alphaStringUpper) {
          newArray.push(alphaIndex);
        }
       var arrayLength = newArray.length;
      }
    }
   countArray.push(arrayLength);
  }

 return countArray;

};

solve();

Answer 1

您可以使用一个对象并存储最后找到的索引加一以供下一次搜索。

function solve() {
    var alphabet = [...'abcdefghijklmnopqrstuvwxyz'];
    var testArray = ["IAMDEFANDJKL", "thedefgh", "xyzDEFghijabc"];
    var countArray = [];

    for (var i = 0; i < testArray.length; i++) {
        var string = testArray[i];
        var newArray = [],
            lastIndex = {};

        for (var char = 0; char < string.length; char++) {
            var character = string[char];
            lastIndex[character] = lastIndex[character] || 0;
            var characterIndex = string.indexOf(character, lastIndex[character]);

            if (characterIndex !== -1) lastIndex[character] = characterIndex + 1;

            for (var alpha = 0; alpha < alphabet.length; alpha++) {
                var alphaString = alphabet[alpha];
                var alphaIndex = alphabet.indexOf(alphaString);
                var characterUpper = character.toUpperCase();
                var alphaStringUpper = alphaString.toUpperCase();

                if (characterIndex === alphaIndex && characterUpper === alphaStringUpper) {
                    newArray.push(alphaIndex);
                }
              var arrayLength = newArray.length;
            }
        }
        countArray.push(arrayLength);
    }
    return countArray;
}

console.log(solve());

通过检查字符串的相同索引来更短的方法。

function solve() {
    var alphabet = 'abcdefghijklmnopqrstuvwxyz',
        testArray = ["IAMDEFANDJKL", "thedefgh", "xyzDEFghijabc"],
        i, j, count, string,
        result = [];

    for (var i = 0; i < testArray.length; i++) {
        count = 0;
        string = testArray[i].toLowerCase();
        for (j = 0; j < string.length; j++) {
            if (string[j] === alphabet[j]) count++;
        }
        result.push(count);
    }
    return result;
}

console.log(solve());