add hw2

node_modules/ramda/es/mapAccum.js

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+import _curry3 from "./internal/_curry3.js";
+/**
+ * The `mapAccum` function behaves like a combination of map and reduce; it
+ * applies a function to each element of a list, passing an accumulating
+ * parameter from left to right, and returning a final value of this
+ * accumulator together with the new list.
+ *
+ * The iterator function receives two arguments, *acc* and *value*, and should
+ * return a tuple *[acc, value]*.
+ *
+ * @func
+ * @memberOf R
+ * @since v0.10.0
+ * @category List
+ * @sig ((acc, x) -> (acc, y)) -> acc -> [x] -> (acc, [y])
+ * @param {Function} fn The function to be called on every element of the input `list`.
+ * @param {*} acc The accumulator value.
+ * @param {Array} list The list to iterate over.
+ * @return {*} The final, accumulated value.
+ * @see R.scan, R.addIndex, R.mapAccumRight
+ * @example
+ *
+ *      const digits = ['1', '2', '3', '4'];
+ *      const appender = (a, b) => [a + b, a + b];
+ *
+ *      R.mapAccum(appender, 0, digits); //=> ['01234', ['01', '012', '0123', '01234']]
+ * @symb R.mapAccum(f, a, [b, c, d]) = [
+ *   f(f(f(a, b)[0], c)[0], d)[0],
+ *   [
+ *     f(a, b)[1],
+ *     f(f(a, b)[0], c)[1],
+ *     f(f(f(a, b)[0], c)[0], d)[1]
+ *   ]
+ * ]
+ */
+
+var mapAccum =
+/*#__PURE__*/
+_curry3(function mapAccum(fn, acc, list) {
+  var idx = 0;
+  var len = list.length;
+  var result = [];
+  var tuple = [acc];
+
+  while (idx < len) {
+    tuple = fn(tuple[0], list[idx]);
+    result[idx] = tuple[1];
+    idx += 1;
+  }
+
+  return [tuple[0], result];
+});
+
+export default mapAccum;