LeetCode [416] Partition Equal Subset Sum

Given a non-empty array 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.

Note:

1. Each of the array element will not exceed 100.
2. The array size will not exceed 200.

Example 1:

Input: [1, 5, 11, 5]

Output: true

Explanation: The array can be partitioned as [1, 5, 5] and [11].

Example 2:

Input: [1, 2, 3, 5]

Output: false

Explanation: The array cannot be partitioned into equal sum subsets.

class Solution { public: bool canPartition(vector& nums) { bitset<10001> bits(1); int sum = accumulate(nums.begin(), nums.end(), 0); for (auto n : nums) bits |= bits << n; return !(sum & 1) && bits[sum >> 1]; } };