From 12e06a76c310d067724a8a8d6f4706f6434b78ff Mon Sep 17 00:00:00 2001
From: RuSaG0 <mirzoev-ruslan-2000@mail.ru>
Date: Thu, 9 Dec 2021 18:10:42 +0300
Subject: [PATCH] findmin

---
 Maths/FindMin.js           | 40 +++++++++++++++++++-------
 Maths/test/FindMin.test.js | 59 +++++++++++++++++++++++++++-----------
 2 files changed, 72 insertions(+), 27 deletions(-)

diff --git a/Maths/FindMin.js b/Maths/FindMin.js
index 9eee78dc7e..93a178c767 100644
--- a/Maths/FindMin.js
+++ b/Maths/FindMin.js
@@ -1,23 +1,41 @@
 /**
  * @function FindMin
  * @description Function to find the minimum number given in an array of integers.
- * @param {Integer[]} nums - Array of Integers
- * @return {Integer} - The minimum number of the array.
  */
 
-const findMin = (...nums) => {
-  if (nums.length === 0) {
-    throw new TypeError('Array is empty')
-  }
+const findMin = (_iterable, _selector = undefined) => {
+  let min = undefined;
+
+  const iterator = _iterable[Symbol.iterator]();
+  if (!_selector) {
+    let current = iterator.next();
+    if(current.done)
+      return undefined;
+    min = current.value;
 
-  let min = nums[0]
-  for (let i = 1; i < nums.length; i++) {
-    if (nums[i] < min) {
-      min = nums[i]
+    current = iterator.next();
+    while(!current.done) {
+      const x = current.value;
+      if(x < min)
+        min = x;
+      current = iterator.next();
     }
   }
+  else {
+    let current = iterator.next();
+    if(current.done)
+      return undefined;
+    min = _selector(current.value);
 
-  return min
+    current = iterator.next();
+    while(!current.done) {
+      const x = _selector(current.value);
+      if(x < min)
+        min = x;
+      current = iterator.next();
+    }
+  }
+  return min;
 }
 
 export { findMin }
diff --git a/Maths/test/FindMin.test.js b/Maths/test/FindMin.test.js
index 85381f80e8..63d87b6c01 100644
--- a/Maths/test/FindMin.test.js
+++ b/Maths/test/FindMin.test.js
@@ -1,18 +1,45 @@
 import { findMin } from '../FindMin'
 
-describe('FindMin', () => {
-  test('Should return the minimum number in the array', () => {
-    const min = findMin(2, 5, 1, 12, 43, 1, 9)
-    expect(min).toBe(1)
-  })
-
-  test('Should return the minimum number in the array', () => {
-    const min = findMin(21, 513, 6)
-    expect(min).toBe(6)
-  })
-
-  test('Should throw error', () => {
-    const min = () => findMin()
-    expect(min).toThrow('Array is empty')
-  })
-})
+describe('findMin', () => {
+  // ----------------------------------------------------------------------
+  test('given empty array then min is undefined', () => {
+    expect(findMin([])).toBeUndefined();
+  });
+  // ----------------------------------------------------------------------
+  test('given single value array then min is found', () => {
+    expect(findMin([1])).toBe(1);
+    expect(findMin([-1])).toBe(-1);
+    expect(findMin([0])).toBe(0);
+  });
+  // ----------------------------------------------------------------------
+  test('given array then min is found', () => {
+    expect(findMin([1,2])).toBe(1);
+    expect(findMin([-1,10])).toBe(-1);
+    expect(findMin([0,100])).toBe(0);
+    expect(findMin([100,0])).toBe(0);
+    expect(findMin([100,50,20,0,-100,0,2,30,45,99,104,23])).toBe(-100);
+  });
+  // ----------------------------------------------------------------------
+  test('given empty generator then min is undefined', () => {
+    const src = function*(){}
+    expect(findMin(src())).toBeUndefined();
+  });
+  // ----------------------------------------------------------------------
+  test('given generator then min is found', () => {
+    const src = function*(){
+      yield 1;
+      yield -1;
+      yield 0;
+    }
+    expect(findMin(src())).toBe(-1);
+  });
+  // ----------------------------------------------------------------------
+  test('given string generator then min string length is found', () => {
+    const src = function*(){
+      yield "abc";
+      yield "de";
+      yield "qwerty";
+    }
+    expect(findMin(src(),_x=>_x.length)).toBe(2);
+  });
+});
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