Merge pull request #225 from majvax/snippets-c++

[Snippets-C++] Added two snippets from #209

Author: majvax

snippets/cpp/array-manipulation/filter-vector.md renamed to snippets/cpp/vector-manipulation.md/filter.md

@@ -1,5 +1,5 @@
 ---
-Title: Filter Vector
+Title: Filter
 Description: Filters a vector using a predicate function.
 Author: majvax
 Tags: array,filter,c++23

snippets/cpp/vector-manipulation.md/remove-duplicates.md

@@ -0,0 +1,29 @@
+---
+title: Remove duplicates
+description: Removes duplicates from an vector of ints
+author: AnkushRoy-code
+tags: vector,remove,duplicate
+contributor: majvax
+---
+
+```cpp
+#include <algorithm>
+#include <vector>
+
+bool removeDuplicates(std::vector<int> &input) noexcept {
+    if (input.empty()) return false;
+    const auto size = input.size();
+    std::sort(input.begin(), input.end());
+
+    auto last = std::unique(input.begin(), input.end()); // remove duplicates
+    input.erase(last, input.end()); // resize vector and delete the undefined elements
+
+    return size != input.size();
+}
+
+
+
+// Usage:
+std::vector<int> vec = {4, 2, 2, 8, 5, 6, 9, 9, 9, 8, 8, 4};
+removeDuplicates(vec); // returns {2, 4, 5, 6, 8, 9}
+```

snippets/cpp/vector-manipulation.md/remove-n-occurences.md

@@ -0,0 +1,39 @@
+---
+title: Remove n Occurences
+description: Removes duplicates from an vector of ints
+author: AnkushRoy-code
+tags: vector,remove
+contributor: majvax
+---
+
+```cpp
+#include <algorithm>
+#include <unordered_map>
+#include <vector>
+
+bool removeOccurrences(std::vector<int>& vec, const unsigned int n) noexcept {
+    if (vec.empty() || n == 0) return false;
+
+    const auto size = vec.size();
+    std::unordered_map<int, int> frequency; // count frequencies
+    for (int num : vec) {
+        frequency[num]++;
+    }
+
+    vec.erase( // remove elements with n number of occurrences
+        std::remove_if(vec.begin(), vec.end(), [&frequency, n](const int x) {
+            return frequency[x] == n;
+        }),
+        vec.end()
+    );
+    return size != vec.size();
+}
+
+
+
+// Usage:
+std::vector<int> vec = {4, 2, 4, 8, 5, 6, 8, 8, 4, 3 };
+
+int n = 3; // Remove elements that occur exactly 3 times
+removeOccurrences(vec, n); // returns {2, 5, 6, 3}
+```

snippets/cpp/array-manipulation/transform-vector.md renamed to snippets/cpp/vector-manipulation.md/transform.md

@@ -1,5 +1,5 @@
 ---
-Title: Transform Vector
+Title: Transform
 Description: Transforms a vector using a function.
 Author: majvax
 Tags: array,transform,c++23