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.

The above elevation map is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain water (blue section) are being trapped.Thanks Marcos for contributing this image!

int trap(int A[], int n)
{
	int left[n];
	int right[n];
	int leftMax = 0;
	for (int i = 0; i < n; i++)
	{
		left[i] = leftMax;
		leftMax = max(leftMax, A[i]);
	}

	int rightMax = 0;
	for (int i = n-1; i >= 0; i--)
	{
		right[i] = rightMax;
		rightMax = max(rightMax, A[i]);
	}

	int result = 0;

	for (int i = 0; i < n; i++)
	{
		int temp = min(left[i], right[i]) - A[i];
		if (temp > 0)
		{
			result += temp;
		}
	}

	return result;
}