add 1615

Author: yinghaoyu

README.md

@@ -73,6 +73,7 @@ LeetCode Solution In Hard Way
 |1624|[Largest Substring Between Two Equal Characters](https://leetcode.cn/problems/largest-substring-between-two-equal-characters/) | [C++](./src/Problem_1624_maxLengthBetweenEqualCharacters.cc)|Easy|
 |1620|[Coordinate With Maximum Network Quality](https://leetcode.cn/problems/coordinate-with-maximum-network-quality/) | [C++](./src/Problem_1620_bestCoordinate.cc)|Medium|
 |1619|[Mean of Array After Removing Some Elements](https://leetcode.cn/problems/mean-of-array-after-removing-some-elements/) | [C++](./src/Problem_1619_trimMean.cc)|Easy|
+|1615|[Maximal Network Rank](https://leetcode.cn/problems/maximal-network-rank/) | [C++](./src/Problem_1615_maximalNetworkRank.cc)|Medium|
 |1604|[Alert Using Same Key-Card Three or More Times in a One Hour Period](https://leetcode.cn/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period/) | [C++](./src/Problem_1604_alertNames.cc)|Medium|
 |1592|[Rearrange Spaces Between Words](https://leetcode.cn/problems/rearrange-spaces-between-words/) | [C++](./src/Problem_1592_reorderSpaces.cc)|Easy|
 |1590|[Make Sum Divisible by P](https://leetcode.cn/problems/make-sum-divisible-by-p/) | [C++](./src/Problem_1590_minSubarray.cc)|Medium|

src/Problem_1615_maximalNetworkRank.cc

@@ -0,0 +1,52 @@
+#include <iostream>
+#include <iterator>
+#include <vector>
+
+#include "UnitTest.h"
+
+using namespace std;
+
+class Solution
+{
+ public:
+  int maximalNetworkRank(int n, vector<vector<int>> &roads)
+  {
+    vector<vector<bool>> connect(n, vector<bool>(n));
+    vector<int> degree(n);
+    for (auto &v : roads)
+    {
+      connect[v[0]][v[1]] = true;
+      connect[v[1]][v[0]] = true;
+      degree[v[0]]++;
+      degree[v[1]]++;
+    }
+    int max = 0;
+    for (int i = 0; i < n; i++)
+    {
+      for (int j = i + 1; j < n; j++)
+      {
+        int rank = degree[i] + degree[j] - (connect[i][j] ? 1 : 0);
+        max = std::max(max, rank);
+      }
+    }
+    return max;
+  }
+};
+
+void testMaximalNetworkRank()
+{
+  Solution s;
+  vector<vector<int>> n1 = {{0, 1}, {0, 3}, {1, 2}, {1, 3}};
+  vector<vector<int>> n2 = {{0, 1}, {0, 3}, {1, 2}, {1, 3}, {2, 3}, {2, 4}};
+  vector<vector<int>> n3 = {{0, 1}, {1, 2}, {2, 3}, {2, 4}, {5, 6}, {5, 7}};
+  EXPECT_EQ_INT(4, s.maximalNetworkRank(4, n1));
+  EXPECT_EQ_INT(5, s.maximalNetworkRank(5, n2));
+  EXPECT_EQ_INT(5, s.maximalNetworkRank(8, n3));
+  EXPECT_SUMMARY;
+}
+
+int main()
+{
+  testMaximalNetworkRank();
+  return 0;
+}