Data commit

Task/Ranking-methods/Java/ranking-methods.java

@@ -0,0 +1,75 @@
+import java.util.*;
+
+public class RankingMethods {
+
+    final static String[] input = {"44 Solomon", "42 Jason", "42 Errol",
+        "41 Garry", "41 Bernard", "41 Barry", "39 Stephen"};
+
+    public static void main(String[] args) {
+        int len = input.length;
+
+        Map<String, int[]> map = new TreeMap<>((a, b) -> b.compareTo(a));
+        for (int i = 0; i < len; i++) {
+            String key = input[i].split("\\s+")[0];
+            int[] arr;
+            if ((arr = map.get(key)) == null)
+                arr = new int[]{i, 0};
+            arr[1]++;
+            map.put(key, arr);
+        }
+        int[][] groups = map.values().toArray(new int[map.size()][]);
+
+        standardRanking(len, groups);
+        modifiedRanking(len, groups);
+        denseRanking(len, groups);
+        ordinalRanking(len);
+        fractionalRanking(len, groups);
+    }
+
+    private static void standardRanking(int len, int[][] groups) {
+        System.out.println("\nStandard ranking");
+        for (int i = 0, rank = 0, group = 0; i < len; i++) {
+            if (group < groups.length && i == groups[group][0]) {
+                rank = i + 1;
+                group++;
+            }
+            System.out.printf("%d %s%n", rank, input[i]);
+        }
+    }
+
+    private static void modifiedRanking(int len, int[][] groups) {
+        System.out.println("\nModified ranking");
+        for (int i = 0, rank = 0, group = 0; i < len; i++) {
+            if (group < groups.length && i == groups[group][0])
+                rank += groups[group++][1];
+            System.out.printf("%d %s%n", rank, input[i]);
+        }
+    }
+
+    private static void denseRanking(int len, int[][] groups) {
+        System.out.println("\nDense ranking");
+        for (int i = 0, rank = 0; i < len; i++) {
+            if (rank < groups.length && i == groups[rank][0])
+                rank++;
+            System.out.printf("%d %s%n", rank, input[i]);
+        }
+    }
+
+    private static void ordinalRanking(int len) {
+        System.out.println("\nOrdinal ranking");
+        for (int i = 0; i < len; i++)
+            System.out.printf("%d %s%n", i + 1, input[i]);
+    }
+
+    private static void fractionalRanking(int len, int[][] groups) {
+        System.out.println("\nFractional ranking");
+        float rank = 0;
+        for (int i = 0, tmp = 0, group = 0; i < len; i++) {
+            if (group < groups.length && i == groups[group][0]) {
+                tmp += groups[group++][1];
+                rank = (i + 1 + tmp) / 2.0F;
+            }
+            System.out.printf("%2.1f %s%n", rank, input[i]);
+        }
+    }
+}