1 files changed, 73 insertions, 0 deletions
diff --git a/challenge-208/roger-bell-west/javascript/ch-2.js b/challenge-208/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..49ebe84e79
--- /dev/null
+++ b/challenge-208/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,73 @@
+#! /usr/bin/node
+
+"use strict"
+
+// by Frank Tan
+// https://stackoverflow.com/questions/38400594/javascript-deep-comparison
+function deepEqual(a,b)
+{
+    if( (typeof a == 'object' && a != null) &&
+        (typeof b == 'object' && b != null) )
+    {
+        var count = [0,0];
+        for( var key in a) count[0]++;
+        for( var key in b) count[1]++;
+        if( count[0]-count[1] != 0) {return false;}
+        for( var key in a)
+        {
+            if(!(key in b) || !deepEqual(a[key],b[key])) {return false;}
+        }
+        for( var key in b)
+        {
+            if(!(key in a) || !deepEqual(b[key],a[key])) {return false;}
+        }
+        return true;
+    }
+    else
+    {
+        return a === b;
+    }
+}
+
+function duplicateandmissing(a) {
+    let flags = 0;
+    let dup = 0;
+    let mis = 0;
+    let exp = a[0] + 1;
+    for (let n of a.slice(1)) {
+        if (n < exp) {
+            dup = n
+            flags |= 1;
+        } else if (n > exp) {
+            mis = exp;
+            flags |= 2;
+        }
+        if (flags == 3) {
+            return [dup, mis];
+        }
+        exp = n + 1;
+    }
+    if (flags == 1) {
+        return [dup, exp];
+    }
+    return [-1];
+}
+
+if (deepEqual(duplicateandmissing([1, 2, 2, 4]), [2, 3])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(duplicateandmissing([1, 2, 3, 4]), [-1])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(duplicateandmissing([1, 2, 3, 3]), [3, 4])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");