How to push data to 2d array with predefined result

Question

I have several inputs, let's say here are two inputs like the following:

const first = 50;
const second = [[14, 16], [28, 30]];

How can i get the following result:

expected result = [[0, 13], [14, 16], [17, 27], [28, 30], [31, 50]];

Now my code is like this and still confused to arrange the correct logic, thank you

const first = 50;
const second = [[14, 16], [28, 30]].flat(1);

let result = [];
for(let i = 0; i < second.length; i++) {
   let temp = second[i];
   if (i === 0) {
     result.push([i, temp - 1]);
   }
   result.push([i+temp, temp+2]);
}

console.log(result); // output [[0, 13], [14, 16], [17, 18], [30, 30], [33, 32]]

DEMO

What if `first` is greater than the smallest value in `second`, or smaller than the largest value in `second`? — Nick, Oct 11 '22 at 05:42

score 0 · Accepted Answer · answered Oct 11 '22 at 05:48

When iterating over the array of arrays. push the array being iterated over itself to the result. Examine its second value to determine where the next iteration should start at.

const first = 50;
const second = [[14, 16], [28, 30]];

const result = [];
let start = 0;
while (second.length) {
  const secondItem = second.shift();
  result.push([start, secondItem[0] - 1]);
  result.push(secondItem);
  start = secondItem[1] + 1;
}
if (start < first) {
  result.push([start, first]);
}
console.log(result);

Hi could you help me here? https://stackoverflow.com/q/74015538/15916627 — Hello World, Oct 11 '22 at 06:39

How to push data to 2d array with predefined result

1 Answers1