How can I change the length of each table to be equal to the longest one provided that the longest one has a length greater than or equal to 5?

user_8499517 0
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Let's assume that I have a 2D array in typescript. Exactly in the source code it looks like this:

    tsvData: any;
    this.tsvData = this.UploaderService.tsvData.split("\n").map(function(row){return row.split("\t");});

I would like to change the length of each table to be equal to the longest one provided that the longest one has a length greater than or equal to 5. If the length of the longest table is less than 5 I would like to change the length of each table to 5. I would like to fill the missing places with an empty string. I add two examples for understanding what my goal is. In addition, I would like to delete all arrays with empty strings.

Example 1

In this example the longest array is equals to 4 so I change the length of each table to 5.

Input:

[["text1", "text2", "text3", "text4"], 
["text5", "text6"], 
["text7"],
["text8", "text9", "text10"],
[""]]

Output:

[["text1", "text2", "text3", "text4", ""], 
["text5", "text6", "", "", ""], 
["text7", "", "", "", ""],
["text8", "text9", "text10", "", ""]]

Example 2

In this example the longest array is equals to 6 so I change the length of each table to 6.

Input:

[["text1", "text2", "text3", "text4"], 
["text5", "text6"], 
["text7"],
["text8", "text9", "text10", "text11", "text12", "text13"],
[""]]

Output:

[["text1", "text2", "text3", "text4", "", ""], 
["text5", "text6", "", "", "", ""], 
["text7", "", "", "", "", ""],
["text8", "text9", "text10", "text11", "text12", "text13"]]
angular6 angular typescript multidimensional-array arrays
2 Answers

First step would be to find the sub-array of maximum size.

let arr = [["text1", "text2", "text3", "text4"], 
            ["text5", "text6"], 
            ["text7"],
            ["text8", "text9", "text10"],
            [""]];

arr = arr.filter(e => e.every(x => x !== ""))    

const maxLength = Math.max(...arr.map(a => a.length));

The next step is to fill the array with blank values.

arr.forEach(e => {
    while(e.length < maxLength){
        e.push("");
    }
});

console.log(arr);

I am sure there are better ways of doing it as the time complexity of the algorithm is O(n2)

user_2598890

Let's break it down into steps:

  1. Find the max length in the arrays of the 2D array.
  2. Check if it's >= 5. Based on this, create a maxLength.
  3. Then loop through the 2D array, create the rest array and fill it with "".
  4. Merge the rest array with each item of the 2D array.

Try this:

var initialTime = performance.now();

var array1 = [
  ["text1", "text2", "text3", "text4"], 
  ["text5", "text6"], 
  ["text7"],
  ["text8", "text9", "text10"],
  [""]
];

var array2 = [
  ["text1", "text2", "text3", "text4"], 
  ["text5", "text6"], 
  ["text7"],
  ["text8", "text9", "text10", "text11", "text12", "text13"],
  [""]
];

function fillRestItems(arrays) {
  var maxArrayLength = Math
    .max(...arrays.map(array => array.length));

  var maxLength = maxArrayLength >= 5 ? maxArrayLength : 5;

  return arrays
  .map(arr => {
    if(!(arr.length === 1 && arr[0] === "")) {
      var addedArray = new Array(maxLength - arr.length).fill("");
      return [...arr, ...addedArray];
    }
  })
  .filter(array => array !== undefined);
}

console.log('Filled Array 1:', fillRestItems(array1));
console.log('Filled Array 2: ', fillRestItems(array2));

var finalTime = performance.now();
console.log(`This took: ${(finalTime - initialTime)} ms`);

user_26222920
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