题解 | 一种不需要双指针的O(n+m)的简单做法，一样快速

代码：

int L[10001], R[10001];
class Solution {
  public:

    int ans = 0, minh = 1e9, maxh = -1;
    int maxArea(vector<int>& height) {
        for (int i = 0; i < 10001; i++) {
            L[i] = 1e9;
            R[i] = -1;
        }
        for (int i = 0; i < height.size(); i++) {
            int h = height[i];
            L[h] = min(L[h], i);
            R[h] = max(R[h], i);
            minh = min(minh, h);
            maxh = max(maxh, h);
        }
        int A = R[maxh]; //最大下标
        int B = L[maxh]; //最小下标
        ans = 0;
        for (int i = maxh; i >= minh; i--) {
            A = max(A, R[i]);
            B = min(B, L[i]);
            int sz1 = A - L[i]; //高-矮
            int sz2 = R[i] - B; //
            ans = max(ans, i * max(sz1, sz2));
        }
        return ans;
    }
};