Created GayleShapeyAlgorithm.cpp

GayleShapeyAlgorithm.cpp

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+// C++ program for stable marriage problem
+#include <iostream>
+#include <string.h>
+#include <stdio.h>
+using namespace std;
+
+// Number of Men or Women
+#define N 4
+
+// This function returns true if woman 'w' prefers man 'm1' over man 'm'
+bool wPrefersM1OverM(int prefer[2*N][N], int w, int m, int m1)
+{
+	// Check if w prefers m over her current engagement m1
+	for (int i = 0; i < N; i++)
+	{
+		// If m1 comes before m in list of w, then w prefers her
+		// current engagement, don't do anything
+		if (prefer[w][i] == m1)
+			return true;
+
+		// If m comes before m1 in w's list, then free her current
+		// engagement and engage her with m
+		if (prefer[w][i] == m)
+		return false;
+	}
+}
+
+
+void stableMarriage(int prefer[2*N][N])
+{
+
+	int wPartner[N];
+
+	// An array to store availability of men. If mFree[i] is
+	// false, then man 'i' is free, otherwise engaged.
+	bool mFree[N];
+
+	// Initialize all men and women as free
+	memset(wPartner, -1, sizeof(wPartner));
+	memset(mFree, false, sizeof(mFree));
+	int freeCount = N;
+
+	// While there are free men
+	while (freeCount > 0)
+	{
+		// Pick the first free man (we could pick any)
+		int m;
+		for (m = 0; m < N; m++)
+			if (mFree[m] == false)
+				break;
+
+		// One by one go to all women according to m's preferences.
+		// Here m is the picked free man
+		for (int i = 0; i < N && mFree[m] == false; i++)
+		{
+			int w = prefer[m][i];
+			if (wPartner[w-N] == -1)
+			{
+				wPartner[w-N] = m;
+				mFree[m] = true;
+				freeCount--;
+			}
+
+			else // If w is not free
+			{
+				// Find current engagement of w
+				int m1 = wPartner[w-N];
+				if (wPrefersM1OverM(prefer, w, m, m1) == false)
+				{
+					wPartner[w-N] = m;
+					mFree[m] = true;
+					mFree[m1] = false;
+				}
+			} // End of Else
+		} // End of the for loop that goes to all women in m's list
+	} // End of main while loop
+
+
+	// Print the solution
+	cout << "Woman Man" << endl;
+	for (int i = 0; i < N; i++)
+	cout << " " << i+N << "\t" << wPartner[i] << endl;
+}
+
+// Driver program to test above functions
+int main()
+{
+	int prefer[2*N][N] = { {7, 5, 6, 4},
+		{5, 4, 6, 7},
+		{4, 5, 6, 7},
+		{4, 5, 6, 7},
+		{0, 1, 2, 3},
+		{0, 1, 2, 3},
+		{0, 1, 2, 3},
+		{0, 1, 2, 3},
+	};
+	stableMarriage(prefer);
+
+	return 0;
+}