[LeetCode11]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.

Analysis:

For any container, the volume depends on the shortest board.

Use two pointers, scan from the start and end, to store the maximum volume.

Java

public int maxArea(int[] height) {
		if(height.length<2) return 0;
		int maxV = 0;
		int start =0;
		int end = height.length-1;
		while(start<end){
			int area = Math.min(height[start], height[end])*(end-start);
			maxV = Math.max(maxV, area);
			if(height[start]>height[end])
				end--;
			else {
				start++;
			}
		}
		return maxV;
    }

c++

int maxArea(vector<int> &height) {
    int start =0;
      int end = height.size()-1;
     int maxV = INT_MIN;
      while(start<end)
      {
        int contain = min(height[end], height[start]) * (end-start);
        maxV = max(maxV, contain);
        if(height[start]<= height[end])
        {
          start++;
        }
        else
        {
          end--;
        }
      }
      return maxV;
}