Create Quadratic-Assignment-Problem.cpp

Coding/C++/Quadratic-Assignment-Problem.cpp

@@ -0,0 +1,72 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int calculateTotalCost(const vector<vector<int>>& facilities, const vector<vector<int>>& locations, const vector<int>& assignment) {
+	int totalCost = 0;
+	int n = facilities.size();
+
+	for (int i = 0; i < n; i++) {
+		for (int j = 0; j < n; j++) {
+			int facility1 = assignment[i];
+			int facility2 = assignment[j];
+			int location1 = i;
+			int location2 = j;
+
+			totalCost += facilities[facility1][facility2] * locations[location1][location2];
+		}
+	}
+
+	return totalCost;
+}
+
+int main() {
+	// Facilities cost matrix
+	vector<vector<int>> facilities = {
+		{0, 2, 3, 1},
+		{2, 0, 1, 4},
+		{3, 1, 0, 2},
+		{1, 4, 2, 0}
+	};
+
+	// Flow matrix
+	vector<vector<int>> locations = {
+		{0, 1, 2, 3},
+		{1, 0, 4, 2},
+		{2, 4, 0, 1},
+		{3, 2, 1, 0}
+	};
+
+	int n = facilities.size();
+
+	// Generate initial assignment (0, 1, 2, 3)
+	vector<int> assignment(n);
+	for (int i = 0; i < n; i++) {
+		assignment[i] = i;
+	}
+
+	// Calculate the initial total cost
+	int minCost = calculateTotalCost(facilities, locations, assignment);
+	vector<int> minAssignment = assignment;
+
+	// Generate all permutations of the assignment
+	while (next_permutation(assignment.begin(), assignment.end())) {
+		int cost = calculateTotalCost(facilities, locations, assignment);
+		if (cost < minCost) {
+			minCost = cost;
+			minAssignment = assignment;
+		}
+	}
+
+	// Print the optimal assignment and total cost
+	cout << "Optimal Assignment: ";
+	for (int i = 0; i < n; i++) {
+		cout << "F" << (minAssignment[i] + 1) << "->L" << (i + 1) << " ";
+	}
+	cout << endl;
+	cout << "Total Cost: " << minCost << endl;
+
+	return 0;
+}