P011 Container With Most Water

Given n non-negative integers a1, a2, …, an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container.

思路分析

• 类似于二分查找的策略
• 从两头开始逐渐向中间靠拢

代码

java

public class Solution011 {
    public int maxArea(int[] height) {
        if (height == null || height.length < 2)
            return 0;
        int max = 0;
        int left = 0;
        int right = height.length - 1;
        while (left < right) {
            int tmp = (right - left) * Math.min(height[left], height[right]);
            if (tmp > max)
                max = tmp;
            if (height[left] < height[right])
                left++;
            else
                right--;
        }
        return max;
    }

}

python

class Solution011(object):
    def maxArea(self, height):
        """
        :type height: List[int]
        :rtype: int
        """
        if not height or len(height) < 2:
            return 0
        ret = 0
        l = 0;r = len(height) - 1;
        while l < r:
            tmp = (r - l) * min(height[l], height[r])
            if tmp > ret:ret = tmp
            if height[l] < height[r]:
                l += 1
            else:
                r -= 1

        return ret