leetcode/cpp/0978.cpp at master · xfmeng17/leetcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
class Solution {
public:
  int maxTurbulenceSize(vector<int> &A) {
    // return func1(A);
    return func2(A);
  }

  // ** two 1D array dp
  int func1(vector<int> &A) {
    int N = A.size();
    if (N <= 1) {
      return N;
    }

    vector<int> more(N, 1);
    vector<int> less(N, 1);
    int res = 0;

    for (int i = 1; i < N; i++) {
      if (A[i - 1] < A[i]) {
        more[i] = max(more[i], less[i - 1] + 1);
      } else if (A[i - 1] > A[i]) {
        less[i] = max(less[i], more[i - 1] + 1);
      }
      res = max(res, max(more[i], less[i]));
    }

    return res;
  }

  int func2(vector<int> &A) {
    int N = A.size();
    if (N <= 1) {
      return N;
    }

    int more = 1;
    int less = 1;
    int res = 1;

    for (int i = 1; i < N; i++) {
      if (A[i - 1] < A[i]) {
        more = less + 1;
        less = 1;
      } else if (A[i - 1] > A[i]) {
        less = more + 1;
        more = 1;
      } else {
        more = 1;
        less = 1;
      }
      // cout<<"x="<<A[i]<<", more="<<more<<", less="<<less<<endl;
      res = max(res, max(more, less));
    }

    return res;
  }
};