Non-decreasing Array 非递减数列

/**
 * references:
 * https://www.cnblogs.com/grandyang/p/7565424.html
 * @brief The Solution class
 * Given an array with n integers, your task is to check if it
 * could become non-decreasing by modifying at most 1element.

We define an array is non-decreasing if array[i] <= array[i + 1] holds for every i (1 <= i < n).

Example 1:

Input: [4,2,3]
Output: True
Explanation: You could modify the first 4 to 1 to get a non-decreasing array.
Example 2:
Input: [4,2,1]
Output: False
Explanation: You can't get a non-decreasing array by modify at most one element.
Note: The n belongs to [1, 10,000].
这道题给了我们一个数组，说我们最多有1次修改某个数字的机会，问能不能将数组变为非递减数组。
题目中给的例子太少，不能覆盖所有情况，我们再来看下面三个例子：

4，2，3

-1，4，2，3

2，3，3，2，4
 *
*/

/**
 * @总结：
 * 1，通过举例子覆盖所有用例，从而辅助写代码
 */
class Solution{
public:
    bool checkPossibility(vector<int>& nums){
        int cnt = 1,n = nums.size();
        for(int i = 1; i < n; i++){
            if(nums[i] < nums[i-1]){
                if(cnt == 0) return false;
                if(i == 1 || nums[i] >= nums[i-2])
                    nums[i-1] = nums[i];
                else
                    nums[i] = nums[i-1];
                --cnt;
            }
        }
        return true;
    }
};