tasks a-s

Task/Self-describing-numbers/JavaScript/self-describing-numbers.js

@@ -0,0 +1,28 @@
+function is_self_describing(n) {
+    var digits = Number(n).toString().split("").map(function(elem) {return Number(elem)});
+    var len = digits.length;
+    var count = digits.map(function(x){return 0});
+
+    digits.forEach(function(digit, idx, ary) {
+        if (digit >= count.length)
+            return false
+        count[digit] ++;
+    });
+
+    return digits.equals(count);
+}
+
+Array.prototype.equals = function(other) {
+    if (this === other)
+        return true;  // same object
+    if (this.length != other.length)
+        return false;
+    for (idx in this)
+        if (this[idx] !== other[idx])
+            return false;
+    return true;
+}
+
+for (var i=1; i<=3300000; i++)
+    if (is_self_describing(i))
+        print(i);