public int trap(int[] height) {
		if(height==null||height.length<=2)
			return 0;
		int len = height.length-1;
		int sum = 0;
		int start = 0;
		if(height[1]>height[0])
			 start = findNextHighPoint(height,0);
//		if(isLog)
//			System.out.println("start "+start);
		for(int i=start;i<len-1;i++){
			int left = i;
			int right = findNextHighPoint(height, i);
//			if(isLog)
//				System.out.println(i+" right:"+right);
			if(right >0){
				sum+=calc(height,left,right);
				i=right-1;
			}else{
				break;
			}
		}
		return sum;
	}