Medium
Count Strictly Increasing Subarrays — C++
Full explanation · Time O(n) · Space O(1)
// Time: O(n)
// Space: O(1)
// two pointers
class Solution {
public:
long long countSubarrays(vector<int>& nums) {
int64_t result = 1, l = 1;
for (int i = 1; i < size(nums); ++i) {
if (nums[i - 1] >= nums[i]) {
l = 0;
}
result += ++l;
}
return result;
}
};
// Time: O(n)
// Space: O(1)
// two pointers
class Solution2 {
public:
long long countSubarrays(vector<int>& nums) {
int64_t result = 0, left = 0;
for (int64_t right = 0; right < size(nums); ++right) {
if (!(right - 1 >= 0 && nums[right - 1] < nums[right])) {
left = right;
}
result += right - left + 1;
}
return result;
}
};