Update README with LeetCode Daily Challenge

Author: jeremymanning

README.md

@@ -337,6 +337,7 @@ _**Note:** Our group is currently taking a break from grinding leetcode. The tab
 | May 20, 2025 | [3355](https://leetcode.com/problems/zero-array-transformation-i/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/3355) | 🟡 Medium |
 | May 21, 2025 | [73](https://leetcode.com/problems/set-matrix-zeroes/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/73) | 🟡 Medium |
 | May 22, 2025 | [3362](https://leetcode.com/problems/zero-array-transformation-iii/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/3362) | 🟡 Medium |
+| May 23, 2025 | [3068](https://leetcode.com/problems/find-the-maximum-sum-of-node-values/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/3068) | 🔴 Hard |
 
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