# Partition To K Equal Sum Subsets Problem

## Description

LeetCode Problem 698.

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:

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

Example 2:

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

Constraints:

• 1 <= k <= nums.length <= 16
• 1 <= nums[i] <= 10^4
• The frequency of each element is in the range [1, 4].

## Sample C++ Code

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class Solution {
public:
bool checkPar(vector<int>& nums, vector<int>& visited,
int target, int curr_sum, int idx, int k) {
if (k == 1)
return true;
if (curr_sum == target)
return checkPar(nums, visited, target, 0, 0, k-1);
for (int i = idx; i < nums.size(); i ++) {
if ((visited[i] == 0) && (curr_sum+nums[i]<=target)) {
visited[i] = 1;
if (checkPar(nums, visited, target, curr_sum+nums[i], i+1, k))
return true;
visited[i] = 0;
}
}
return false;
}
bool canPartitionKSubsets(vector<int>& nums, int k) {
int len = nums.size();
int target = 0;
vector<int> visited(len, 0);
for (int i = 0; i < len; i ++)
target += nums[i];
if (target % k != 0)
return false;

return checkPar(nums, visited, target/k, 0, 0, k);
}
};
``````