Add Round Robin and Least Connections load balancing algorithms

code/networking/src/load_balancing.cpp

@@ -0,0 +1,49 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <queue>
+
+using namespace std;
+
+// Round Robin implementation
+// Returns the selected server name. 'index' is updated to point to the next server.
+string round_robin(const vector<string>& servers, int& index) {
+    if (servers.empty()) return "<no-server>";
+    string server = servers[index];
+    index = (index + 1) % servers.size();
+    return server;
+}
+
+// Least Connections implementation (min-heap of (connections, server_index))
+// Returns the server index with least connections (or -1 if none).
+int least_connections(const priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>& minHeap) {
+    if (minHeap.empty()) return -1;
+    return minHeap.top().second;
+}
+
+int main() {
+    vector<string> servers = {"Server1", "Server2", "Server3"};
+    int idx = 0;
+
+    // Demonstrate round-robin selection and show the index after selection
+    cout << "Round Robin selection 1: " << round_robin(servers, idx) << " | index = " << idx << endl;
+    cout << "Round Robin selection 2: " << round_robin(servers, idx) << " | index = " << idx << endl;
+    cout << "Round Robin selection 3: " << round_robin(servers, idx) << " | index = " << idx << endl;
+    cout << "Round Robin selection 4: " << round_robin(servers, idx) << " | index = " << idx << endl;
+
+    // Least connections: using a min-heap of (connection_count, server_index)
+    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> minHeap;
+    minHeap.push({3, 0});
+    minHeap.push({1, 1});
+    minHeap.push({5, 2});
+
+    int leastIdx = least_connections(minHeap);
+    if (leastIdx >= 0) {
+        cout << "Least Connections → Server index: " << leastIdx
+             << " (" << servers[leastIdx] << ")" << endl;
+    } else {
+        cout << "Least Connections → no servers available" << endl;
+    }
+
+    return 0;
+}