add 354

Author: luliyucoordinate

Diff for: README.md

@@ -227,6 +227,7 @@ LeetCode
 |0347|[Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/) | c | [c++](./src/0347-Top-K-Frequent-Elements/0347.cpp) |[python](./src/0347-Top-K-Frequent-Elements/0347.py)|||Medium|
 |0349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/) | c | [c++](./src/0349-Intersection-of-Two-Arrays/0349.cpp) |[python](./src/0349-Intersection-of-Two-Arrays/0349.py)|||Easy|
 |0350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/) | c | [c++](./src/0350-Intersection-of-Two-Arrays-II/0350.cpp) |[python](./src/0350-Intersection-of-Two-Arrays-II/0350.py)|||Easy|
+|0354|[Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/) | c | [c++](./src/0354-Russian-Doll-Envelopes/0354.cpp) |[python](./src/0354-Russian-Doll-Envelopes/0354.py)|||Hard|
 |0377|[Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/) | c | [c++](./src/0377-Combination-Sum-IV/0377.cpp) |[python](./src/0377-Combination-Sum-IV/0377.py)|||Medium|
 |0389|[Find the Difference](https://leetcode.com/problems/find-the-difference/) | c | [c++](./src/0389-Find-the-Difference/0389.cpp) |[python](./src/0389-Find-the-Difference/0389.py)|||Easy|
 |0392|[Is Subsequence](https://leetcode.com/problems/is-subsequence/) | c | [c++](./src/0392-Is-Subsequence/0392.cpp) |[python](./src/0392-Is-Subsequence/0392.py)|||Medium|

Diff for: src/0354-Russian-Doll-Envelopes/0354.cpp

@@ -0,0 +1,20 @@
+static int x = []() {std::ios::sync_with_stdio(false); cin.tie(0); return 0; }();
+class Solution 
+{
+public:
+    int maxEnvelopes(vector<pair<int, int>>& envelopes) 
+    {
+        sort(envelopes.begin(), envelopes.end(), [](const pair<int, int>& a, const pair<int, int>& b){
+            return a.first < b.first || (a.first == b.first and a.second > b.second);
+        });
+        
+        vector<int> mem;
+        for (auto& e : envelopes)
+        {
+            auto index = lower_bound(mem.begin(), mem.end(), e.second);
+            if (index == mem.end()) mem.push_back(e.second);
+            else *index = e.second;
+        }
+        return mem.size();
+    }
+};

Diff for: src/0354-Russian-Doll-Envelopes/0354.py

@@ -0,0 +1,16 @@
+from bisect import bisect_left
+class Solution:
+    def maxEnvelopes(self, envelopes: List[List[int]]) -> int:
+        if not envelopes:
+            return 0
+        
+        res, n = 0, len(envelopes)
+        envelopes.sort(key=lambda a:(a[0], -a[1]))
+        mem = list()
+        for e in envelopes:
+            index = bisect_left(mem, e[1])
+            if len(mem) == index:
+                mem.append(e[1])
+            else:
+                mem[index] = e[1]
+        return len(mem)