public class Solution {
public boolean canPartition(int[] nums) {
if (nums == null || nums.length == 0) return false;
int sum = 0, n = nums.length;
for (int num : nums) {
sum += num;
}
if ((sum & 1) == 1) return false;
sum /= 2;
boolean[][] dp = new boolean[n + 1][sum + 1];
dp[0][0] = true;
for (int i = 1; i < n + 1; i++) {
dp[i][0] = true;
}
for (int i = 1; i < n + 1; i++) {
for (int j = 1; j < sum + 1; j++) {
dp[i][j] = dp[i - 1][j];
if (j >= nums[i - 1]) {
dp[i][j] = (dp[i][j] || dp[i - 1][j - nums[i - 1]]);
}
}
}
return dp[n][sum];
}
}