✨ [q7] First attemp

Author: enkr1

7/README.md

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+https://leetcode.com/problems/reverse-integer/
+
+# Question
+
+Given a signed 32-bit integer `x`, return `x` *with its digits reversed*. If reversing `x` causes the value to go outside the signed 32-bit integer range `[-231, 231 - 1]`, then return `0`.
+
+**Assume the environment does not allow you to store 64-bit integers (signed or unsigned).**
+
+**Example 1:**
+
+```
+Input: x = 123
+Output: 321
+```
+
+**Example 2:**
+
+```
+Input: x = -123
+Output: -321
+```
+
+**Example 3:**
+
+```
+Input: x = 120
+Output: 21
+```
+
+**Constraints:**
+
+- `231 <= x <= 231 - 1`

7/my_solution.js

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+/**
+ * @param {number} x
+ * @return {number}
+ */
+const reverse = (x) => {
+  let charList = x.toString().split(''), result = null;
+  // charList.forEach((char, i) => {
+  //   console.log("char")
+  //   console.log(char)
+  //   console.log(i)
+  //   console.log("parseInt(char[i]) * i")
+  //   console.log(parseInt(char[i]) * i)
+  //   result += parseInt(char[i]) * i;
+  //   i *= 10;
+  // })
+
+  result = reverseCharList(charList, 0, 1, null);
+
+  console.log("result")
+  console.log(result)
+};
+
+const reverseCharList = (charList, i, factor, result) => {
+  if (undefined === charList[i]) return result;
+  console.log("charList[i]")
+  console.log(charList[i])
+
+  result += (parseInt(charList[i]) * factor);
+  factor *= 10;
+  console.log("result")
+  console.log(result)
+  console.log("factor")
+  console.log(factor)
+
+  i++;
+  return reverseCharList(charList, i, factor, result);
+}
+
+
+// reverse(321)
+reverse(120)

7/solution.js

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+/**
+ * @param {number} x
+ * @return {number}
+ */
+const reverse = (x) => {
+  return reverseCharList(x.toString().split(''), 0, 1, null);
+};
+
+const reverseCharList = (charList, i, factor, result) => {
+  if (undefined === charList[i]) return result;
+
+  result += (parseInt(charList[i]) * factor);
+  factor *= 10;
+  i++;
+
+  return reverseCharList(charList, i, factor, result);
+}
+