trapping the rain water
class Solution { public: int trap(vector<int>& height) { vector<int>a; vector<int>b; min[height[i-1],height[i+1]]; for(int i=0;i<height.size()-1;i++){ if(height[i]<height[i+1] && height[i]<height[i-1]){ min[height[i-1],height[i+1]];; } } } };