Number of ways to partition an array into subsets with equal sum?

public int CountPartitions(int[] nums) {

int sum = 0;

foreach (int num in nums) sum += num;

if (sum % 2 != 0) return 0;

int target = sum / 2;

int[] dp = new int[target + 1];

dp[0] = 1;

Follow on:

foreach (int num in nums) {

for (int j = target; j >= num; j--) {

dp[j] += dp[j - num];

return dp[target];

Explanation:

Classic subset sum DP. dp[j] = ways to get sum j. Counting subsets summing to half the

total.