add Fish

Author: talgat-ruby

README.md

@@ -32,7 +32,7 @@
         -   ~~NumberOfDiscIntersections~~
     -   [Lesson 7 - Stacks and Queues](#s_7)
         -   [Brackets](#s_7_brackets)
-        -   ~~Fish~~
+        -   [Fish](#s_7_fish)
         -   [Nesting](#s_7_nesting)
 -   [Licence](#licence)
 
@@ -304,6 +304,18 @@ https://github.com/talgat-ruby/codility-lessons-javascript/blob/master/lesson7_s
 
 https://app.codility.com/demo/results/trainingDYK3SU-2EQ/
 
+<a name="s_7_fish"></a>
+
+#### Fish
+
+##### File
+
+https://github.com/talgat-ruby/codility-lessons-javascript/blob/master/lesson7_stacks_and_queues/Fish.js
+
+##### Link to Report
+
+https://app.codility.com/demo/results/trainingZRRPA4-NVP/
+
 <a name="s_7_nesting"></a>
 
 #### Nesting

lesson7_stacks_and_queues/Fish.js

@@ -0,0 +1,22 @@
+function solution(A, B) {
+    const len = A.length;
+    const down = []; // B[i] === 1
+    let counter = 0;
+    for (let i = 0; i < len; i++) {
+        const size = A[i];
+        const direction = B[i];
+        if (direction === 1) {
+            down.push(size);
+        } else {
+            while (down.length > 0 && size > down[down.length - 1]) {
+                down.pop();
+            }
+            if (down.length === 0) {
+                counter++;
+            }
+        }
+    }
+    return counter + down.length;
+}
+
+module.exports = solution;

lesson7_stacks_and_queues/Fish.test.js

@@ -0,0 +1,7 @@
+const solution = require("./Fish");
+
+describe("test Fish", () => {
+    test("([4, 3, 2, 1, 5], [0, 1, 0, 0, 0]) -> 2", () => {
+        expect(solution([4, 3, 2, 1, 5], [0, 1, 0, 0, 0])).toBe(2);
+    });
+});