LeetCode_581. Shortest Unsorted Continuous Subarray

题目描述：

class Solution {
public:
    int findUnsortedSubarray(vector<int>& nums) {
        vector<int>::iterator itb=nums.begin();
        vector<int>::iterator ite=nums.end();
        vector<int> copy(itb,ite);
        sort(copy.begin(),copy.end());
        int i=0,j=nums.size()-1;
        while(i<copy.size()){
            if(copy[i]!=nums[i])
                break;
            i++;
        }
        while(j>=0){
            if(copy[j]!=nums[j])
                break;
            j--;
        }
        return i<=j?j-i+1:0;
    }
};      

class Solution {
public:
    int findUnsortedSubarray(vector<int>& nums) {
        int min=INT_MIN,max=INT_MAX;
        int end=0,start=nums.size()-1;
        int n=nums.size();
        for(int i=0;i<nums.size();i++){
            if(nums[i]>=min){
                min=nums[i];
                end++;
            }else
                end=0;
            if(nums[n-1-i]<=max){
                max=nums[n-1-i];
                start++;
            }else
                start=0;
        }
        return std::max(0,n-end-start);
    }
};