Merge pull request youngyangyang04#2389 from eeee0717/master

Update.买卖股票的最佳时机2，添加C#

Author: youngyangyang04

problems/0045.跳跃游戏II.md

@@ -464,6 +464,27 @@ impl Solution {
     }
 }
 ```
+### C#
+```csharp
+// 版本二
+public class Solution
+{
+    public int Jump(int[] nums)
+    {
+        int cur = 0, next = 0, step = 0;
+        for (int i = 0; i < nums.Length - 1; i++)
+        {
+            next = Math.Max(next, i + nums[i]);
+            if (i == cur)
+            {
+                cur = next;
+                step++;
+            }
+        }
+        return step;
+    }
+}
+```
 
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problems/0055.跳跃游戏.md

@@ -258,6 +258,23 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public bool CanJump(int[] nums)
+    {
+        int cover = 0;
+        if (nums.Length == 1) return true;
+        for (int i = 0; i <= cover; i++)
+        {
+            cover = Math.Max(i + nums[i], cover);
+            if (cover >= nums.Length - 1) return true;
+        }
+        return false;
+    }
+}
+```
 
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problems/0122.买卖股票的最佳时机II.md

@@ -406,6 +406,21 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public int MaxProfit(int[] prices)
+    {
+        int res = 0;
+        for (int i = 0; i < prices.Length - 1; i++)
+        {
+            res += Math.Max(0, prices[i + 1] - prices[i]);
+        }
+        return res;
+    }
+}
+```
 
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problems/0134.加油站.md

@@ -630,6 +630,29 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+// 贪心算法，方法二
+public class Solution
+{
+    public int CanCompleteCircuit(int[] gas, int[] cost)
+    {
+        int curSum = 0, totalSum = 0, start = 0;
+        for (int i = 0; i < gas.Length; i++)
+        {
+            curSum += gas[i] - cost[i];
+            totalSum += gas[i] - cost[i];
+            if (curSum < 0)
+            {
+                start = i + 1;
+                curSum = 0;
+            }
+        }
+        if (totalSum < 0) return -1;
+        return start;
+    }
+}
+```
 
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problems/0135.分发糖果.md

@@ -370,6 +370,35 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public int Candy(int[] ratings)
+    {
+        int[] candies = new int[ratings.Length];
+        for (int i = 0; i < candies.Length; i++)
+        {
+            candies[i] = 1;
+        }
+        for (int i = 1; i < ratings.Length; i++)
+        {
+            if (ratings[i] > ratings[i - 1])
+            {
+                candies[i] = candies[i - 1] + 1;
+            }
+        }
+        for (int i = ratings.Length - 2; i >= 0; i--)
+        {
+            if (ratings[i] > ratings[i + 1])
+            {
+                candies[i] = Math.Max(candies[i], candies[i + 1] + 1);
+            }
+        }
+        return candies.Sum();
+    }
+}
+```
 
 
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problems/0860.柠檬水找零.md

@@ -397,6 +397,46 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public bool LemonadeChange(int[] bills)
+    {
+        int five = 0, ten = 0, twenty = 0;
+        foreach (var bill in bills)
+        {
+            if (bill == 5) five++;
+            if (bill == 10)
+            {
+                if (five == 0) return false;
+                five--;
+                ten++;
+            }
+            if (bill == 20)
+            {
+                if (ten > 0 && five > 0)
+                {
+                    ten--;
+                    five--;
+                    twenty++;
+                } 
+                else if (five >= 3)
+                {
+                    five -= 3;
+                    twenty++;
+                }
+                else
+                {
+                    return false;
+                }
+
+            }
+        }
+        return true;
+    }
+}
+```
 
 
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problems/1005.K次取反后最大化的数组和.md

@@ -322,6 +322,29 @@ object Solution {
 }
 ```
 
+### C#
+```csharp
+public class Solution
+{
+    public int LargestSumAfterKNegations(int[] nums, int k)
+    {
+        int res = 0;
+        Array.Sort(nums, (a, b) => Math.Abs(b) - Math.Abs(a));
+        for (int i = 0; i < nums.Length; i++)
+        {
+            if (nums[i] < 0 && k > 0)
+            {
+                nums[i] *= -1;
+                k--;
+            }
+        }
+        if (k % 2 == 1) nums[nums.Length - 1] *= -1;
+        foreach (var item in nums) res += item;
+        return res;
+    }
+}
+```
+
 
 
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