Java for LeetCode 042 Trapping Rain Water

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.

For example,
Given [0,1,0,2,1,0,1,3,2,1,2,1], return 6.

解题思路：

先找到第一块最高的木板，然后从前向最高木板遍历，接着从后向最高木板遍历，JAVA实现如下：

    static public int trap(int[] height) {
    	int result=0,peak=0,firstMax=0;
    	for(int i=0;i<height.length;i++)
    		if(height[i]>height[firstMax])
    			firstMax=i;
    	for(int i=0;i<firstMax;i++)
    		if(height[i]>height[peak])
    			peak=i;
    		else result+=height[peak]-height[i];
    	peak=height.length-1;
    	for(int i=height.length-1;i>firstMax;i--)
    		if(height[i]>height[peak])
    			peak=i;
    		else result+=height[peak]-height[i];
        return result;
    }