Permutations

LeetCode

Commonly asked at:Amazon Microsoft Google

Permutations

Given an array of distinct integers, return the count of all possible orderings.

Example

Input: 1 2 3 Output: 6

Approach

At each step, pick any one of the still-unused numbers next, recurse on the rest, and count a complete permutation once every number has been placed. This branches into exactly n! leaves.

Input format

Line 1: the array, space-separated

Print the total number of permutations.

Not solved yet

Ctrl+Enter

Editor

nums = list(map(int, input().split()))
result = []
# TODO: backtrack(path, remaining) — base case: remaining is empty
def bt(path, remaining):
    if not remaining:
        result.append(list(path))
        return

nums = list(map(int, input().split()))
result = []
# TODO: backtrack(path, remaining) — base case: remaining is empty
def bt(path, remaining):
    if not remaining:
        result.append(list(path))
        return

Input (stdin)

Output

Run your code to see output here.

Isolated sandbox · not executed on your devicePowered by Judge0 CE (free, self-hosted). Runs in an isolated sandbox — not on your device.

Editor

nums = list(map(int, input().split()))
result = []
# TODO: backtrack(path, remaining) — base case: remaining is empty
def bt(path, remaining):
    if not remaining:
        result.append(list(path))
        return

nums = list(map(int, input().split()))
result = []
# TODO: backtrack(path, remaining) — base case: remaining is empty
def bt(path, remaining):
    if not remaining:
        result.append(list(path))
        return

Input (stdin)

Output

Run your code to see output here.

Isolated sandbox · not executed on your devicePowered by Judge0 CE (free, self-hosted). Runs in an isolated sandbox — not on your device.

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Permutations

Permutations

Example

Approach

Input format

Permutations

Permutations

Example

Approach

Input format

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