11. 盛最多水的容器

class Solution {
public:
  int maxArea(vector<int>& height) {
    int l = 0, r = height.size() - 1;
    int Result = 0;
    while (l != r) {
      // You can in fact see the thinking process here. The effective height is
      // always the MINIMUM of two heights-
      int EffectiveHeight = min(height[l], height[r]);
      int Width = r - l;
      Result = max(Result, EffectiveHeight * Width);
      // And that's why we always choose the shortest one to advance.
      if (height[l] < height[r])
        ++l;
      else
        --r;
    }
    return Result;
  }
};

class Solution {
public:
  int maxArea(vector<int>& height) {
    int MaxArea = 0;
    int L = 0, R = height.size() - 1;
    while (L != R) {
      int LH = height[L];
      int RH = height[R];
      int Area = (R - L) * min(LH, RH);
      MaxArea = std::max(MaxArea, Area);
      // Use while-loop to fast-forward pointers. Not really needed but this
      // coincidentally looks exactly like how we do in QuickSort.
      if (LH < RH)
        while (L != R && height[++L] < LH);
      else
        while (L != R && height[--R] < RH);
    }
    return MaxArea;
  }
};