LeetCode-in-All
416. Partition Equal Subset Sum
Medium
Given a non-empty array nums containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal.
Example 1:
Input: nums = [1,5,11,5]
Output: true
Explanation: The array can be partitioned as [1, 5, 5] and [11].
Example 2:
Input: nums = [1,2,3,5]
Output: false
Explanation: The array cannot be partitioned into equal sum subsets.
Constraints:
1 <= nums.length <= 2001 <= nums[i] <= 100
Solution
class Solution {
func canPartition(_ nums: [Int]) -> Bool {
var sums = nums.reduce(0, +)
if sums % 2 == 1 {
return false
}
sums /= 2
var dp = [Bool](repeating: false, count: sums + 1)
dp[0] = true
for num in nums {
for sum in stride(from: sums, through: num, by: -1) {
dp[sum] = dp[sum] || dp[sum - num]
}
}
return dp[sums]
}
}