Monotonic Array Problem & Solution
An array is monotonic if it is either monotone increasing or monotone decreasing.
An array nums is monotone increasing if for all i <= j, nums[i] <= nums[j].
An array nums is monotone decreasing if for all i <= j, nums[i] >= nums[j].
Given an integer array nums, return true if the given array is monotonic, or false otherwise.
See the monotonic array problem on LeetCode.
C++ Solution
#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")
static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();
class Solution {
public:
bool isMonotonic(vector<int>& nums) {
bool increasing = true;
bool decreasing = true;
for (int i = 1; i < nums.size(); ++i) {
increasing &= nums[i - 1] <= nums[i];
decreasing &= nums[i - 1] >= nums[i];
}
return increasing || decreasing;
}
};