how to get distinct combinations of a set in typescript

You can obtain distinct combinations of a set by implementing a recursive approach that generates all possible combinations using backtracking techniques.

Here's an example implementation that takes a set of numbers as input and outputs the distinct combinations without duplicates:

index.ts
function getCombinations(set: Set<number>): Set<Set<number>> {
  const combinations = new Set<Set<number>>();
  const nums = Array.from(set);

  function backtrack(start: number, currentSet: Set<number>) {
    combinations.add(currentSet);

    for (let i = start; i < nums.length; i++) {
      const newSet = new Set(currentSet);
      newSet.add(nums[i]);
      backtrack(i + 1, newSet);
    }
  }

  backtrack(0, new Set());
  return combinations;
}
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The backtrack function is responsible for generating all possible combinations. It starts with an empty set, adds it to the combinations set, and then recursively adds all possible combinations of subsets by choosing elements from the input set from the starting index to the end.

To prevent duplicates, we use the Set datatype to keep track of current subsets that have already been added to the combinations set.

Finally, we call the getCombinations function with a set of numbers to obtain all distinct combinations:

index.ts
const inputSet = new Set<number>([1, 2, 3]);
const combinations = getCombinations(inputSet);

console.log([...combinations]); // [ Set {}, Set { 1 }, Set { 2 }, Set { 3 }, Set { 1, 2 }, Set { 1, 3 }, Set { 2, 3 }, Set { 1, 2, 3 } ]
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Note that the output is a set of sets, where each inner set represents a distinct combination of elements from the input set.