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26 changes: 26 additions & 0 deletions solution/0000-0099/0063.Unique Paths II/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,32 @@
## 解法
<!-- 这里可写通用的实现逻辑 -->

### Go
``` go
func uniquePathsWithObstacles(obstacleGrid [][]int) int {
m,n := len(obstacleGrid),len(obstacleGrid[0])
dp := make([][]int,m)
for i:=0; i < m;i++ {
dp[i] = make([]int,n)
}
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
if obstacleGrid[i][j] == 0 {
if i == 0 && j == 0 {
dp[i][j] = 1
} else if i > 0 && j >0 {
dp[i][j] = dp[i][j-1]+dp[i-1][j]
} else if i > 0 {
dp[i][j] = dp[i-1][j]
} else {
dp[i][j] = dp[i][j-1]
}
}
}
}
return dp[m-1][n-1]
}


### Python3
<!-- 这里可写当前语言的特殊实现逻辑 -->
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111 changes: 82 additions & 29 deletions solution/0000-0099/0063.Unique Paths II/README_EN.md
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@@ -1,40 +1,93 @@
# [63. Unique Paths II](https://leetcode.com/problems/unique-paths-ii)

## Description
<p>A robot is located at the top-left corner of a <em>m</em> x <em>n</em> grid (marked &#39;Start&#39; in the diagram below).</p>

<p>The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked &#39;Finish&#39; in the diagram below).</p>

<p>Now consider if some obstacles are added to the grids. How many unique paths would there be?</p>

<p><img src="https://assets.leetcode.com/uploads/2018/10/22/robot_maze.png" style="width: 400px; height: 183px;" /></p>

<p>An obstacle and empty space is marked as <code>1</code> and <code>0</code> respectively in the grid.</p>

<p><strong>Note:</strong> <em>m</em> and <em>n</em> will be at most 100.</p>

<p><strong>Example 1:</strong></p>

<pre>
<strong>Input:
</strong>[
&nbsp; [0,0,0],
&nbsp; [0,1,0],
&nbsp; [0,0,0]
]
<strong>Output:</strong> 2
<strong>Explanation:</strong>
There is one obstacle in the middle of the 3x3 grid above.
There are two ways to reach the bottom-right corner:
1. Right -&gt; Right -&gt; Down -&gt; Down
2. Down -&gt; Down -&gt; Right -&gt; Right
</pre>
<p>A robot is located at the top-left corner of a <em>m</em> x <em>n</em> grid (marked &#39;Start&#39; in the diagram below).</p>



## Solutions
<p>The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked &#39;Finish&#39; in the diagram below).</p>



<p>Now consider if some obstacles are added to the grids. How many unique paths would there be?</p>



<p><img src="https://assets.leetcode.com/uploads/2018/10/22/robot_maze.png" style="width: 400px; height: 183px;" /></p>



<p>An obstacle and empty space is marked as <code>1</code> and <code>0</code> respectively in the grid.</p>



<p><strong>Note:</strong> <em>m</em> and <em>n</em> will be at most 100.</p>



<p><strong>Example 1:</strong></p>



<pre>

<strong>Input:

</strong>[

&nbsp; [0,0,0],

&nbsp; [0,1,0],

&nbsp; [0,0,0]

]

<strong>Output:</strong> 2

<strong>Explanation:</strong>

There is one obstacle in the middle of the 3x3 grid above.

There are two ways to reach the bottom-right corner:

1. Right -&gt; Right -&gt; Down -&gt; Down

2. Down -&gt; Down -&gt; Right -&gt; Right

</pre>




## Solutions

### Go
```go
func uniquePathsWithObstacles(obstacleGrid [][]int) int {
m,n := len(obstacleGrid),len(obstacleGrid[0])
dp := make([][]int,m)
for i:=0; i < m;i++ {
dp[i] = make([]int,n)
}
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
if obstacleGrid[i][j] == 0 {
if i == 0 && j == 0 {
dp[i][j] = 1
} else if i > 0 && j >0 {
dp[i][j] = dp[i][j-1]+dp[i-1][j]
} else if i > 0 {
dp[i][j] = dp[i-1][j]
} else {
dp[i][j] = dp[i][j-1]
}
}
}
}
return dp[m-1][n-1]
}
```
### Python3

```python
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23 changes: 23 additions & 0 deletions solution/0000-0099/0063.Unique Paths II/Solution.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
func uniquePathsWithObstacles(obstacleGrid [][]int) int {
m,n := len(obstacleGrid),len(obstacleGrid[0])
dp := make([][]int,m)
for i:=0; i < m;i++ {
dp[i] = make([]int,n)
}
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
if obstacleGrid[i][j] == 0 {
if i == 0 && j == 0 {
dp[i][j] = 1
} else if i > 0 && j >0 {
dp[i][j] = dp[i][j-1]+dp[i-1][j]
} else if i > 0 {
dp[i][j] = dp[i-1][j]
} else {
dp[i][j] = dp[i][j-1]
}
}
}
}
return dp[m-1][n-1]
}