Count the Hidden Sequences LeetCode solution in Java

1
class Solution {
2
  public int numberOfArrays(int[] differences, int lower, int upper) {
3
    ArrayList<Integer> ans = new ArrayList<>();
4
    ans.add(lower);
5
    int mn = lower;
6
    int mx = lower;
7

8
    for (int i = 0; i < differences.length; i++) {
9
      int d = differences[i];
10
      ans.add(d + ans.get(ans.size() - 1));
11
      mn = Math.min(mn, ans.get(ans.size() - 1));
12
      mx = Math.max(mx, ans.get(ans.size() - 1));
13
    }
14

15
    int add = lower - mn;
16

17
    for (int i = 0; i < ans.size(); i++) {
18
      ans.set(i, ans.get(i) + add);
19
    }
20

21
    for (int i = 0; i < ans.size(); i++) {
22
      if (ans.get(i) < lower || upper < ans.get(i)) {
23
        return 0;
24
      }
25
    }
26

27
    int add2 = upper - mx;
28

29
    return add2 - add + 1;
30
  }
31
}