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 {
bool canPartition(List<int> nums) {
int sums = nums.reduce((a, b) => a + b);
if (sums % 2 == 1) {
return false;
}
sums ~/= 2; // Integer division
List<bool> dp = List.filled(sums + 1, false);
dp[0] = true;
for (int num in nums) {
for (int sum = sums; sum >= num; sum--) {
dp[sum] = dp[sum] || dp[sum - num];
}
}
return dp[sums];
}
}