upload code for the algorithm

Author: Csaba79-coder

src/main/java/csaba79coder/GaleShapleyAlgorithmApp.java

@@ -1,8 +1,29 @@
 package csaba79coder;
 
+import csaba79coder.model.GaleShapley;
+
 public class GaleShapleyAlgorithmApp {
 
     public static void main(String[] args) {
 
+        System.out.println("Gale Shapley Marriage Algorithm\n");
+
+        String[] m = {"M1", "M2", "M3", "M4", "M5"};
+
+        String[] w = {"W1", "W2", "W3", "W4", "W5"};
+
+        String[][] mp = {{"W5", "W2", "W3", "W4", "W1"},
+                {"W2", "W5", "W1", "W3", "W4"},
+                {"W4", "W3", "W2", "W1", "W5"},
+                {"W1", "W2", "W3", "W4", "W5"},
+                {"W5", "W2", "W3", "W4", "W1"}};
+
+        String[][] wp = {{"M5", "M3", "M4", "M1", "M2"},
+                {"M1", "M2", "M3", "M5", "M4"},
+                {"M4", "M5", "M3", "M2", "M1"},
+                {"M5", "M2", "M1", "M4", "M3"},
+                {"M2", "M1", "M4", "M3", "M5"}};
+
+        GaleShapley gs = new GaleShapley(m, w, mp, wp);
     }
 }

src/main/java/csaba79coder/model/GaleShapley.java

@@ -0,0 +1,84 @@
+package csaba79coder.model;
+
+public class GaleShapley {
+
+    private final int N;
+    private int engagedCount;
+    private final String[][] menPref;
+    private final String[][] womenPref;
+    private final String[] men;
+    private final String[] women;
+    private final String[] womenPartner;
+    private final boolean[] menEngaged;
+
+    public GaleShapley(String[] m, String[] w, String[][] mp, String[][] wp) {
+        N = mp.length;
+        engagedCount = 0;
+        men = m;
+        women = w;
+        menPref = mp;
+        womenPref = wp;
+        menEngaged = new boolean[N];
+        womenPartner = new String[N];
+        calcMatches();
+    }
+
+    private void calcMatches() {
+        while (engagedCount < N) {
+            int free;
+            for (free = 0; free < N; free++)
+                if (!menEngaged[free])
+                    break;
+
+            for (int i = 0; i < N && !menEngaged[free]; i++) {
+                int index = womenIndexOf(menPref[free][i]);
+                if (womenPartner[index] == null) {
+                    womenPartner[index] = men[free];
+                    menEngaged[free] = true;
+                    engagedCount++;
+                }
+                else {
+                    String currentPartner = womenPartner[index];
+                    if (morePreference(currentPartner, men[free], index)) {
+                        womenPartner[index] = men[free];
+                        menEngaged[free] = true;
+                        menEngaged[menIndexOf(currentPartner)] = false;
+                    }
+                }
+            }
+        }
+        printCouples();
+    }
+
+    private boolean morePreference(String curPartner, String newPartner, int index) {
+        for (int i = 0; i < N; i++)
+        {
+            if (womenPref[index][i].equals(newPartner))
+                return true;
+            if (womenPref[index][i].equals(curPartner))
+                return false;
+        }
+        return false;
+    }
+
+    private int menIndexOf(String str) {
+        for (int i = 0; i < N; i++)
+            if (men[i].equals(str))
+                return i;
+        return -1;
+    }
+
+    private int womenIndexOf(String str) {
+        for (int i = 0; i < N; i++)
+            if (women[i].equals(str))
+                return i;
+        return -1;
+    }
+
+    public void printCouples() {
+        System.out.println("Couples are : ");
+        for (int i = 0; i < N; i++) {
+            System.out.println(womenPartner[i] +" "+ women[i]);
+        }
+    }
+}