Add solution #592

Author: JoshCrozier

README.md

@@ -459,6 +459,7 @@
 589|[N-ary Tree Preorder Traversal](./0589-n-ary-tree-preorder-traversal.js)|Easy|
 590|[N-ary Tree Postorder Traversal](./0590-n-ary-tree-postorder-traversal.js)|Easy|
 591|[Tag Validator](./0591-tag-validator.js)|Hard|
+592|[Fraction Addition and Subtraction](./0592-fraction-addition-and-subtraction.js)|Medium|
 594|[Longest Harmonious Subsequence](./0594-longest-harmonious-subsequence.js)|Easy|
 599|[Minimum Index Sum of Two Lists](./0599-minimum-index-sum-of-two-lists.js)|Easy|
 605|[Can Place Flowers](./0605-can-place-flowers.js)|Easy|

solutions/0592-fraction-addition-and-subtraction.js

@@ -0,0 +1,34 @@
+/**
+ * 592. Fraction Addition and Subtraction
+ * https://leetcode.com/problems/fraction-addition-and-subtraction/
+ * Difficulty: Medium
+ *
+ * Given a string expression representing an expression of fraction addition and subtraction,
+ * return the calculation result in string format.
+ *
+ * The final result should be an irreducible fraction. If your final result is an integer,
+ * change it to the format of a fraction that has a denominator 1. So in this case, 2 should
+ * be converted to 2/1.
+ */
+
+/**
+ * @param {string} expression
+ * @return {string}
+ */
+var fractionAddition = function(expression) {
+  const gcdCalc = (a, b) => b === 0 ? a : gcdCalc(b, a % b);
+  const fractions = expression.match(/[+-]?\d+\/\d+/g);
+  let n = 0;
+  let d = 1;
+
+  for (const fraction of fractions) {
+    const [numerator, denominator] = fraction.split('/').map(Number);
+    n = n * denominator + numerator * d;
+    d = d * denominator;
+    const gcd = Math.abs(gcdCalc(n, d));
+    n /= gcd;
+    d /= gcd;
+  }
+
+  return `${n}/${d}`;
+};