Create MissingRanges.java

Author: techieJarek

MissingRanges.java

@@ -0,0 +1,53 @@
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Given a sorted integer array where the range of elements are [0, 99] inclusive, return its
+ * missing ranges.
+ * For example, given [0, 1, 3, 50, 75], return [“2”, “4->49”, “51->74”, “76->99”]
+ */
+
+public class MissingRanges {
+    public static void main(String[] args) {
+        int[] array = new int[5];
+
+        array[0] = 0;
+        array[1] = 1;
+        array[2] = 3;
+        array[3] = 50;
+        array[4] = 75;
+
+        int min = 1;
+        int max = 99;
+
+        getMissingRanges(array, min, max).forEach(range -> {
+            System.out.println("Range : " + range);
+        });
+    }
+
+    private static List<String> getMissingRanges(int[] array, int min, int max) {
+        List<String> ranges = new ArrayList<>();
+
+        if(array[0] > min) ranges.add(getRange(min, array[0]));
+
+        for(int i=0; i<array.length; i++){
+            int current = array[i];
+            int prev = (i==0) ? -1 : array[i - 1];
+            if(prev == -1) continue;
+            if(current - prev > 1) ranges.add(getRange(prev+1, current-1));
+        }
+
+        if(array[array.length - 1] < max) ranges.add(getRange(array[array.length - 1], max));
+
+        return ranges;
+    }
+
+    private static String getRange(int start, int end) {
+        if(end - start == 0){
+            return String.valueOf(start);
+        }
+        else{
+            return String.valueOf(start) + " -> " + String.valueOf(end);
+        }
+    }
+}