0220凤凰花

class Solution {
public:
    bool increasingTriplet(vector<int>& nums) {
        int n=nums.size();
        if(n<3) return false;
        //must initial or cannot compare with min
        vector<int> pa(n,nums[0]),ba(n,nums.back());
        int min,max;
        min=nums[0];
        max=nums[n-1];
        for(int i=1;i<nums.size();++i)
        {
            if(nums[i]<min) min=nums[i];
            pa[i]=min;
        }
        for(int i=n-2;i>=0;--i)
        {
            if(nums[i]>max) max=nums[i];
            ba[i]=max;
        }
        for(int i=0;i<nums.size();++i)
        {
            if(nums[i]>pa[i]&&nums[i]<ba[i]) return true;
        }
        return false;
    }
};