Medium
Find if Array Can Be Sorted — C++
Full explanation · Time O(n) · Space O(1)
// Time: O(n)
// Space: O(1)
// sort
class Solution {
public:
bool canSortArray(vector<int>& nums) {
for (int right = 0, left = 0, mx = 0; right < size(nums); ++right) {
if (right + 1 != size(nums) && __builtin_popcount(nums[right + 1]) == __builtin_popcount(nums[right])) {
continue;
}
if (mx > *min_element(cbegin(nums) + left, cbegin(nums) + right + 1)) {
return false;
}
mx = *max_element(cbegin(nums) + left, cbegin(nums) + right + 1);
left = right + 1;
}
return true;
}
};
// Time: O(nlogn)
// Space: O(1)
// sort
class Solution2 {
public:
bool canSortArray(vector<int>& nums) {
for (int right = 0, left = 0; right < size(nums); ++right) {
if (right + 1 != size(nums) && __builtin_popcount(nums[right + 1]) == __builtin_popcount(nums[right])) {
continue;
}
sort(begin(nums) + left, begin(nums) + right + 1);
left = right + 1;
}
return is_sorted(cbegin(nums), cend(nums));
}
};