Trapping Rain Water
2018-02-22 14:26
162 查看
Given n non-negative integers representing an elevation map where the width of eahc 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.
code Example1:
public static int trap_1(int[] A)
{
int n = A.Length;
int[] left_peak = new int
;
int[] right_peak = new int
;
for(int i = 1; i < n; i++)
{
left_peak[i] = Math.Max(left_peak[i - 1], A[i - 1]);
}
for(int i = n - 2; i >= 0; --i)
{
right_peak[i] = Math.Max(right_peak[i + 1], A[i + 1]);
}
int sum = 0;
for(int i = 0; i < n; i++)
{
int height = Math.Min(left_peak[i],right_peak[i]);
if (height > A[i])
{
sum += height - A[i];
}
}
return sum;
}
Code example 2:
public static int trap_2(int[] A)
{
int n = A.Length;
int peak_index = 0;
for(int i = 0; i < n; i++)
{
if (A[i] > A[peak_index]) peak_index = i;
}
int water = 0;
for(int i = 0, left_peak = 0; i < peak_index; i++)
{
if (A[i] > left_peak) left_peak = A[i];
else water += left_peak - A[i];
}
for(int i = n - 1, right_peak = 0; i < peak_index; i++)
{
if (A[i] > right_peak) right_peak = A[i];
else water += right_peak - A[i];
}
return water;
}
For example,Given [0,1,0,2,1,0,1,3,2,1,2,1] ,return 6.
code Example1:
public static int trap_1(int[] A)
{
int n = A.Length;
int[] left_peak = new int
;
int[] right_peak = new int
;
for(int i = 1; i < n; i++)
{
left_peak[i] = Math.Max(left_peak[i - 1], A[i - 1]);
}
for(int i = n - 2; i >= 0; --i)
{
right_peak[i] = Math.Max(right_peak[i + 1], A[i + 1]);
}
int sum = 0;
for(int i = 0; i < n; i++)
{
int height = Math.Min(left_peak[i],right_peak[i]);
if (height > A[i])
{
sum += height - A[i];
}
}
return sum;
}
Code example 2:
public static int trap_2(int[] A)
{
int n = A.Length;
int peak_index = 0;
for(int i = 0; i < n; i++)
{
if (A[i] > A[peak_index]) peak_index = i;
}
int water = 0;
for(int i = 0, left_peak = 0; i < peak_index; i++)
{
if (A[i] > left_peak) left_peak = A[i];
else water += left_peak - A[i];
}
for(int i = n - 1, right_peak = 0; i < peak_index; i++)
{
if (A[i] > right_peak) right_peak = A[i];
else water += right_peak - A[i];
}
return water;
}
相关文章推荐
- Leetcode Trapping Rain Water
- Trapping Rain Water
- Trapping Rain Water
- Leetcode-Trapping Rain Water
- Trapping Rain Water
- 【LeetCode】Trapping Rain Water解题报告
- [leetcode] Trapping Rain Water
- Trapping Rain Water
- LeetCode42:Trapping Rain Water
- leetcode -- Trapping Rain Water -- 重点
- [leetcode] 42 Trapping Rain Water
- Trapping Rain Water
- Trapping Rain Water II
- 42. Trapping Rain Water
- leetcode--trapping_rain_water
- Leetcode: trapping-rain-water
- LeetCode算法题目:Trapping Rain Water
- Trapping Rain Water II
- leetcode 407. Trapping Rain Water II
- [Leetcode][python]Trapping Rain Water