Javascript获取给定段的所有组合，这些段完全适合给定的大小

function getCombinations(segment, size) {
  const combinations = [];

  function backtrack(startIndex, currentCombination) {
    if (currentCombination.length === size) {
      combinations.push(currentCombination.slice());
      return;
    }

    for (let i = startIndex; i < segment.length; i++) {
      currentCombination.push(segment[i]);
      backtrack(i + 1, currentCombination);
      currentCombination.pop();
    }
  }

  backtrack(0, []);

  return combinations;
}

const segment = [1, 2, 3, 4];
const size = 2;

const combinations = getCombinations(segment, size);
console.log(combinations);

[[1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4]]