add 2570 2579

Author: Danieldu

HashTable/2570.merge-two-2-d-arrays-by-summing-values.cpp

@@ -0,0 +1,36 @@
+/*
+ * @lc app=leetcode id=2570 lang=cpp
+ *
+ * [2570] Merge Two 2D Arrays by Summing Values
+ */
+
+// @lc code=start
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+public:
+    vector<vector<int>> mergeArrays(vector<vector<int>>& nums1, vector<vector<int>>& nums2) {
+        map<int, int> mergedMap;
+
+        for (const auto& num : nums1) {
+            mergedMap[num[0]] += num[1];
+        }
+
+        for (const auto& num : nums2) {
+            mergedMap[num[0]] += num[1];
+        }
+
+        vector<vector<int>> result;
+        result.reserve(mergedMap.size()); 
+
+        for (const auto& [key, value] : mergedMap) {
+            result.emplace_back(vector<int>{key, value});
+        }
+
+        return result;
+    }
+};
+
+// @lc code=end
+

Math/2579.count-total-number-of-colored-cells.cpp

@@ -0,0 +1,15 @@
+/*
+ * @lc app=leetcode id=2579 lang=cpp
+ *
+ * [2579] Count Total Number of Colored Cells
+ */
+
+// @lc code=start
+class Solution {
+public:
+    long long coloredCells(int n) {
+        return 2LL * n * n - 2LL * n + 1;
+    }
+};
+// @lc code=end
+