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| class Solution {
public int wiggleMaxLength(int[] nums) {
List<Integer> list = new ArrayList<>();
for (int num : nums) {
if (list.isEmpty() || list.get(list.size() - 1) != num) {
list.add(num);
}
}
if (list.size() <= 2) {
return list.size();
}
int cnt = 0;
for (int i = 0; i < list.size(); i++) {
if (isExtremum(list, i)) {
cnt++;
}
}
return cnt;
}
private boolean isExtremum(List<Integer> list, int index) {
if (index == 0) {
return !list.get(1).equals(list.get(0));
} else if (index == list.size() - 1) {
return !list.get(list.size() - 1).equals(list.get(list.size() - 2));
}
int left = list.get(index - 1);
int mid = list.get(index);
int right = list.get(index + 1);
if (mid < left && mid < right) {
return true;
} else if (mid > left && mid > right) {
return true;
} else {
return false;
}
}
}
|
