Add nested loops task

Exercises/6-matrix.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const max = matrix => {
+  // Use nested for loop to find max value in 2d matrix
+  // For example max([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
+  // should return 9
+};
+
+module.exports = { max };

Exercises/6-matrix.test

@@ -0,0 +1,13 @@
+({
+  name: 'max',
+  length: [220, 300],
+  cases: [
+    [[[10]], 10],
+    [[[1, 2], [3, 4], [5, 6]], 6],
+    [[[-1, 1], [2, -1], [-1, 0]], 2],
+  ],
+  test: max => {
+    const src = max.toString();
+    if (!src.includes('for (')) throw new Error('Use for loop');
+  }
+})

Solutions/6-matrix.js

@@ -0,0 +1,15 @@
+'use strict';
+
+const max = matrix => {
+  let value = matrix[0][0];
+  for (let i = 0; i < matrix.length; i++) {
+    const row = matrix[i];
+    for (let j = 0; j < row.length; j++) {
+      const cell = row[j];
+      if (value < cell) value = cell;
+    }
+  }
+  return value;
+};
+
+module.exports = { max };