698. Partition to K Equal Sum Subsets LeetCode Solution

In this guide, you will get 698. Partition to K Equal Sum Subsets LeetCode Solution with the best time and space complexity. The solution to Partition to K Equal Sum Subsets problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

  1. Problem Statement
  2. Complexity Analysis
  3. Partition to K Equal Sum Subsets solution in C++
  4. Partition to K Equal Sum Subsets solution in Java
  5. Partition to K Equal Sum Subsets solution in Python
  6. Additional Resources
698. Partition to K Equal Sum Subsets LeetCode Solution image

Problem Statement of Partition to K Equal Sum Subsets

Given an integer array nums and an integer k, return true if it is possible to divide this array into k non-empty subsets whose sums are all equal.

Example 1:

Input: nums = [4,3,2,3,5,2,1], k = 4
Output: true
Explanation: It is possible to divide it into 4 subsets (5), (1, 4), (2,3), (2,3) with equal sums.

Example 2:

Input: nums = [1,2,3,4], k = 3
Output: false

Constraints:

1 <= k <= nums.length <= 16
1 <= nums[i] <= 104
The frequency of each element is in the range [1, 4].

Complexity Analysis

  • Time Complexity: O(2^n)
  • Space Complexity: O(n)

698. Partition to K Equal Sum Subsets LeetCode Solution in C++

class Solution {
 public:
  bool canPartitionKSubsets(vector<int>& nums, int k) {
    const int sum = accumulate(nums.begin(), nums.end(), 0);
    if (sum % k != 0)
      return false;

    const int target = sum / k;  // the target sum of each subset
    if (ranges::any_of(nums, [target](const int num) { return num > target; }))
      return false;

    ranges::sort(nums, greater<>());
    return dfs(nums, 0, k, /*currSum=*/0, target, /*used=*/0);
  }

 private:
  bool dfs(const vector<int>& nums, int s, int remainingGroups, int currSum,
           const int subsetTargetSum, int used) {
    if (remainingGroups == 0)
      return true;
    if (currSum > subsetTargetSum)
      return false;
    if (currSum == subsetTargetSum)  // Find a valid group, so fresh start.
      return dfs(nums, 0, remainingGroups - 1, 0, subsetTargetSum, used);

    for (int i = s; i < nums.size(); ++i) {
      if (used >> i & 1)
        continue;
      if (dfs(nums, i + 1, remainingGroups, currSum + nums[i], subsetTargetSum,
              used | 1 << i))
        return true;
    }

    return false;
  }
};
/* code provided by PROGIEZ */

698. Partition to K Equal Sum Subsets LeetCode Solution in Java

class Solution {
  public boolean canPartitionKSubsets(int[] nums, int k) {
    final int sum = Arrays.stream(nums).sum();
    if (sum % k != 0)
      return false;

    final int target = sum / k; // the target sum of each subset
    if (Arrays.stream(nums).anyMatch(num -> num > target))
      return false;

    return dfs(nums, 0, k, /*currSum=*/0, target, /*used=*/0);
  }

  private boolean dfs(int[] nums, int s, int remainingGroups, int currSum, int subsetTargetSum,
                      int used) {
    if (remainingGroups == 0)
      return true;
    if (currSum > subsetTargetSum)
      return false;
    if (currSum == subsetTargetSum) // Find a valid group, so fresh start.
      return dfs(nums, 0, remainingGroups - 1, 0, subsetTargetSum, used);

    for (int i = s; i < nums.length; ++i) {
      if ((used >> i & 1) == 1)
        continue;
      if (dfs(nums, i + 1, remainingGroups, currSum + nums[i], subsetTargetSum, used | 1 << i))
        return true;
    }

    return false;
  }
}
// code provided by PROGIEZ

698. Partition to K Equal Sum Subsets LeetCode Solution in Python

class Solution:
  def canPartitionKSubsets(self, nums: list[int], k: int) -> bool:
    summ = sum(nums)
    if summ % k != 0:
      return False

    target = summ // k  # the target sum of each subset
    if any(num > target for num in nums):
      return False

    def dfs(s: int, remainingGroups: int, currSum: int, used: int) -> bool:
      if remainingGroups == 0:
        return True
      if currSum > target:
        return False
      if currSum == target:  # Find a valid group, so fresh start.
        return dfs(0, remainingGroups - 1, 0, used)

      for i in range(s, len(nums)):
        if used >> i & 1:
          continue
        if dfs(i + 1, remainingGroups, currSum + nums[i], used | 1 << i):
          return True

      return False

    nums.sort(reverse=True)
    return dfs(0, k, 0, 0)
# code by PROGIEZ

Additional Resources

See also  964. Least Operators to Express Number LeetCode Solution

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