leetcode 554. Brick Wall

最近写新文章总是要审核，审核还特别慢，像我这种排版强迫症经常写完要多次修改排版的真是感觉wt...f!!!。csdn真是奇了怪了，我干啥了吗？难道刷题更新文章频繁还有错了？

There is a brick wall in front of you. The wall is rectangular and has several rows of bricks. The bricks have the same height but different width. You want to draw a vertical line from the top to the bottom and cross the least bricks.

The brick wall is represented by a list of rows. Each row is a list of integers representing the width of each brick in this row from left to right.

If your line go through the edge of a brick, then the brick is not considered as crossed. You need to find out how to draw the line to cross the least bricks and return the number of crossed bricks.

You cannot draw a line just along one of the two vertical edges of the wall, in which case the line will obviously cross no bricks.

Example:

Input: 
[[1,2,2,1],
 [3,1,2],
 [1,3,2],
 [2,4],
 [3,1,2],
 [1,3,1,1]]
Output: 2
Explanation: 

Note:

1. The width sum of bricks in different rows are the same and won't exceed INT_MAX.
2. The number of bricks in each row is in range [1,10,000]. The height of wall is in range [1,10,000]. Total number of bricks of the wall won't exceed 20,000.

这道题只要找准思路就会很简单。

切竖线，我们要尽量找到有很多砖头边的那个竖线位置。所以使用一个map来记录每一层中砖头边出现的位置。当所有层统计完后，哪个位置出现的砖头边越多，那就是我们需要的竖线位置。

package leetcode;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class Brick_Wall_554 {

	public int leastBricks(List> wall) {
		int totalHeight=wall.size();
		HashMap map=new HashMap();
		int maxCount=0;
		for(List list:wall){
			int width=0;
			for(int i=0;imaxCount){
					maxCount=count;
				}
			}
		}
		int result=totalHeight-maxCount;
		return result;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Brick_Wall_554 b=new Brick_Wall_554();
		List> wall=new ArrayList>();
		List list1=new ArrayList();
		list1.add(1);list1.add(2);list1.add(2);list1.add(1);
		List list2=new ArrayList();
		list2.add(3);list2.add(1);list2.add(2);
		List list3=new ArrayList();
		list3.add(1);list3.add(3);list3.add(2);
		List list4=new ArrayList();
		list4.add(2);list4.add(4);
		List list5=new ArrayList();
		list5.add(3);list5.add(1);list5.add(2);
		List list6=new ArrayList();
		list6.add(1);list6.add(3);list6.add(1);list6.add(1);
		wall.add(list1);
		wall.add(list2);
		wall.add(list3);
		wall.add(list4);
		wall.add(list5);
		wall.add(list6);
		System.out.println(b.leastBricks(wall));
	}

}

大神思路跟我一样，嘻嘻，beat了97% submissions.