add Intervals solution

Author: jakovmitrovski

medium300/Intervals.java

@@ -0,0 +1,89 @@
+package medium300;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+
+public class Intervals {
+
+    class Interval {
+        long left, right;
+
+        public Interval(long left, long right) {
+            this.left = left;
+            this.right = right;
+        }
+
+        long getLeft() {
+            return left;
+        }
+    }
+
+    public String smallest(String intervals) {
+
+        String[] ivals = intervals.split(",");
+        List<Interval> list = new ArrayList<>();
+        for (String x : ivals) {
+            String[] in = x.split("-");
+            list.add(new Interval(Long.parseLong(in[0]), Long.parseLong(in[1])));
+        }
+
+        while (true) {
+            boolean change = false;
+            // System.out.println("New iteration");
+            for (int i = 0; i < list.size(); i++) {
+                Interval el = list.get(i);
+
+                for (int j = 0; j < list.size(); j++) {
+                    if (i == j)
+                        continue;
+                    else {
+                        Interval el2 = list.get(j);
+
+                        if (el.right < el2.left - 1 || el.left > el2.right + 1) {
+                            // System.out.println(el.left + "-" + el.right + " is completely outside of " +
+                            // el2.left+"-"+el2.right);
+                            continue;
+                        } else if (el.left <= el2.left && el.right >= el2.right) {
+                            // System.out.println(el.left + "-" + el.right + " contains " +
+                            // el2.left+"-"+el2.right);
+                            list.remove(el2);
+                            change = true;
+                            break;
+                        } else {
+                            // System.out.println(el.left + "-" + el.right + " concatenated with " +
+                            // el2.left+"-"+el2.right);
+                            list.remove(el);
+                            list.remove(el2);
+                            list.add(new Interval(Math.min(el.left, el2.left), Math.max(el.right, el2.right)));
+                            change = true;
+                            break;
+                        }
+                    }
+                }
+            }
+
+            if (!change)
+                break;
+        }
+
+        list.sort(Comparator.comparing(Interval::getLeft));
+        StringBuilder sb = new StringBuilder();
+
+        for (int i = 0; i < list.size(); i++) {
+            Interval el = list.get(i);
+            sb.append(el.left).append("-").append(el.right);
+            if (i != list.size() - 1)
+                sb.append(",");
+        }
+
+        return sb.toString();
+    }
+
+    public static void main(String[] args) {
+        Intervals i = new Intervals();
+        System.out.println(i.smallest("2-4,5-5,6-8"));
+        System.out
+                .println(i.smallest("327802850-593687580,288675425-410271975,386737447-388754878,96575567-222789979"));
+    }
+}