contain_water.py

def contain_water(height):
    max_left, max_right = 0, 0
    left, right = 0, len(height) - 1
    ans = 0

    while left < right:
        if height[left] < height[right]:
            if height[left] > max_left:
                max_left = height[left]
            else:
                ans += max_left - height[left]
            left += 1
        else:
            if height[right] > max_right:
                max_right = height[right]
            else:
                ans += max_right - height[right]
            right -= 1

    return ans

ContainerWithMostWater.c

int maxArea(int* height, int heightSize) {
    int start = 0, end = heightSize - 1;
    int result = 0, area = 0;
    while (start < end) {
        area = (end - start) * (height[start] < height[end] ? height[start] : height[end]);
        result = (result > area ? result : area);
        if (height[start] < height[end]) {
            start ++;
        } else {
            end--;
        }
    }
    return result;
}