665. Non-decreasing Array

题目：

Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element.

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: TrueExplanation: You could modify the first 4 to 1 to get a non-decreasing array.

Example 2:

Input: [4,2,1]Output: FalseExplanation: You can't get a non-decreasing array by modify at most one element.

Note: The n belongs to [1, 10,000].

思路：

本题思路如下：

step1:复制数组nums得nums_c

step2:遍历数组，当当前值小于前一个值时，对两个数组做删除操作，nums删除当前值，nums_c删除前面一个值

step3:分别遍历上述两个数组，当两个数组只要有一个符合非递减返回真，否则返回假

代码：

class Solution {public:    bool checkPossibility(vector<int>& nums) {        vector<int> nums_c = nums;        int flag = 0,flag_c=0;        for(int i=1;i<nums.size();i++)        {            if(nums[i]<nums[i-1])            {                nums.erase(nums.begin()+i-1);                nums_c.erase(nums_c.begin()+i);                break;            }        }        if(count==1)        {            for(int j=1;j<nums.size();j++)        {            if(nums[j]<nums[j-1])            {                flag=1;                break;            }         }             for(int j=1;j<nums.size();j++)        {            if(nums_c[j]<nums_c[j-1])            {                flag_c =1;                break;            }        }        }        if(!flag||!flag_c)            return true;        else             return false;    }};