diff --git a/.eslintrc.js b/.eslintrc.js
index 0026692..c5b9a4b 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -4,29 +4,28 @@ module.exports = {
     node: true,
     jest: true,
   },
-  extends: 'airbnb-base',
+  extends: "airbnb-base",
   overrides: [
     {
       env: {
         node: true,
       },
-      files: [
-        '.eslintrc.{js,cjs}',
-      ],
+      files: [".eslintrc.{js,cjs}"],
       parserOptions: {
-        sourceType: 'script',
+        sourceType: "script",
       },
     },
   ],
   parserOptions: {
-    ecmaVersion: 'latest',
-    sourceType: 'module',
+    ecmaVersion: "latest",
+    sourceType: "module",
   },
   rules: {
-    'operator-assignment': 'off',
-    'max-classes-per-file': 'off',
-    'no-plusplus': 'off',
-    'no-restricted-syntax': 'off',
-    'no-param-reassign': 'off',
+    "operator-assignment": "off",
+    "max-classes-per-file": "off",
+    "no-plusplus": "off",
+    "no-restricted-syntax": "off",
+    "no-param-reassign": "off",
+    quotes: "off",
   },
 };
diff --git a/problem-1/problem-1-1.png b/problem-1/problem-1-1.png
new file mode 100644
index 0000000..326c26e
Binary files /dev/null and b/problem-1/problem-1-1.png differ
diff --git a/problem-1/problem-1.test.js b/problem-1/problem-1.test.js
index f54f840..e639267 100644
--- a/problem-1/problem-1.test.js
+++ b/problem-1/problem-1.test.js
@@ -1,12 +1,25 @@
 const bubbleSort = (array) => {
+  let swapped = false;
+
+  for (let i = 0; i < array.length; i++) {
+    for (let j = 0; j < array.length - 1 - i; j++) {
+      if (array[j] > array[j + 1]) {
+        swapped = true;
+        let temp = array[j];
+        array[j] = array[j + 1];
+        array[j + 1] = temp;
+      }
+    }
+    if (!swapped) return array;
+  }
+  return array;
 };
 
-test.each([
-  [[5, 4, 3, 2, 1]],
-  [[1, 2, 3, 4, 5]],
-  [[4, 2, 1, 5, 3]],
-])('주어진 배열을 오름차순으로 정렬한다', (array) => {
-  bubbleSort(array);
+test.each([[[5, 4, 3, 2, 1]], [[1, 2, 3, 4, 5]], [[4, 2, 1, 5, 3]]])(
+  "주어진 배열을 오름차순으로 정렬한다",
+  (array) => {
+    bubbleSort(array);
 
-  expect(array).toEqual([1, 2, 3, 4, 5]);
-});
+    expect(array).toEqual([1, 2, 3, 4, 5]);
+  },
+);
diff --git a/problem-2/problem-2-2.png b/problem-2/problem-2-2.png
new file mode 100644
index 0000000..8245696
Binary files /dev/null and b/problem-2/problem-2-2.png differ
diff --git a/problem-2/problem-2.test.js b/problem-2/problem-2.test.js
index 1e1fe4f..49987cf 100644
--- a/problem-2/problem-2.test.js
+++ b/problem-2/problem-2.test.js
@@ -1,12 +1,24 @@
 const selectionSort = (array) => {
+  for (let i = 0; i < array.length - 1; i++) {
+    let minIndex = i;
+    for (let j = i + 1; j < array.length; j++) {
+      if (array[j] < array[minIndex]) {
+        minIndex = j;
+      }
+    }
+    if (minIndex !== i) {
+      let temp = array[i];
+      array[i] = array[minIndex];
+      array[minIndex] = temp;
+    }
+  }
 };
 
-test.each([
-  [[5, 4, 3, 2, 1]],
-  [[1, 2, 3, 4, 5]],
-  [[4, 2, 1, 5, 3]],
-])('주어진 배열을 오름차순으로 정렬한다', (array) => {
-  selectionSort(array);
+test.each([[[5, 4, 3, 2, 1]], [[1, 2, 3, 4, 5]], [[4, 2, 1, 5, 3]]])(
+  "주어진 배열을 오름차순으로 정렬한다",
+  (array) => {
+    selectionSort(array);
 
-  expect(array).toEqual([1, 2, 3, 4, 5]);
-});
+    expect(array).toEqual([1, 2, 3, 4, 5]);
+  },
+);
diff --git a/problem-3/problem-3-2.png b/problem-3/problem-3-2.png
new file mode 100644
index 0000000..d2a7da2
Binary files /dev/null and b/problem-3/problem-3-2.png differ
diff --git a/problem-3/problem-3.test.js b/problem-3/problem-3.test.js
index e4450b5..a481595 100644
--- a/problem-3/problem-3.test.js
+++ b/problem-3/problem-3.test.js
@@ -1,12 +1,32 @@
+const exchange = (list, a, b) => {
+  [list[b], list[a]] = [list[a], list[b]];
+};
+
+const less = (a, b) => a < b;
+
 const insertionSort = (array) => {
+  const { length } = array;
+
+  for (let i = 1; i < length; i++) {
+    for (let j = i; j > 0; j--) {
+      if (array[j] < array[j - 1]) {
+        [array[j - 1], array[j]] = [array[j], array[j - 1]];
+      } else {
+        break;
+      }
+    }
+  }
 };
 
-test.each([
-  [[5, 4, 3, 2, 1]],
-  [[1, 2, 3, 4, 5]],
-  [[4, 2, 1, 5, 3]],
-])('주어진 배열을 오름차순으로 정렬한다', (array) => {
-  insertionSort(array);
+// 테스트
+let array = [5, 3, 8, 1, 2];
+console.log(insertionSort(array)); // [1, 2, 3, 5, 8]
+
+test.each([[[5, 4, 3, 2, 1]], [[1, 2, 3, 4, 5]], [[4, 2, 1, 5, 3]]])(
+  "주어진 배열을 오름차순으로 정렬한다",
+  (array) => {
+    insertionSort(array);
 
-  expect(array).toEqual([1, 2, 3, 4, 5]);
-});
+    expect(array).toEqual([1, 2, 3, 4, 5]);
+  },
+);