Permutations of a given string

Print all permutations of a given string.

Hint

Begin at the first letter.

• Swap: We swap the first letter with every other letter in the word.
• Recurse: For each swap, we pretend the first letter is fixed and repeat the swapping process for the remaining letters.
• Backtrack: After exploring all swaps for a particular position, we swap the letters back to their original order to try other possibilities.

Continue this process for each position in the word. Once we've reached the end of the word, we have found one complete arrangement (permutation).

• Python
• Javascript
•  Run

s = "abc"
output = []

def swap(ls, i, j):
  ls[i], ls[j] = ls[j], ls[i]

def permute(ls, idx):
  if idx == len(ls) - 1:
    output.append("".join(ls))
    return

  for i in range(idx, len(ls)):
    swap(ls, idx, i)
    permute(ls, idx + 1)
    swap(ls, idx, i)

permute(list(s), 0)

print(output)

const data = "abc";
const output = [];

function swap(list, i, j) {
  [list[i], list[j]] = [list[j], list[i]];
}

function permute(list, idx) {
  if (idx === list.length) {
    output.push(list.join(""));
    return;
  }

  for (let i = idx; i < list.length; i++) {
    swap(list, idx, i);
    permute(list, idx + 1);
    swap(list, idx, i);
  }
}

permute(data.split(""), 0);

console.log(output);