Add solution #860

Author: JoshCrozier

README.md

@@ -667,6 +667,7 @@
 857|[Minimum Cost to Hire K Workers](./0857-minimum-cost-to-hire-k-workers.js)|Hard|
 858|[Mirror Reflection](./0858-mirror-reflection.js)|Medium|
 859|[Buddy Strings](./0859-buddy-strings.js)|Easy|
+860|[Lemonade Change](./0860-lemonade-change.js)|Easy|
 867|[Transpose Matrix](./0867-transpose-matrix.js)|Easy|
 868|[Binary Gap](./0868-binary-gap.js)|Easy|
 872|[Leaf-Similar Trees](./0872-leaf-similar-trees.js)|Easy|

solutions/0860-lemonade-change.js

@@ -0,0 +1,45 @@
+/**
+ * 860. Lemonade Change
+ * https://leetcode.com/problems/lemonade-change/
+ * Difficulty: Easy
+ *
+ * At a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you
+ * and order one at a time (in the order specified by bills). Each customer will only buy one
+ * lemonade and pay with either a $5, $10, or $20 bill. You must provide the correct change to
+ * each customer so that the net transaction is that the customer pays $5.
+ *
+ * Note that you do not have any change in hand at first.
+ *
+ * Given an integer array bills where bills[i] is the bill the ith customer pays, return true if
+ * you can provide every customer with the correct change, or false otherwise.
+ */
+
+/**
+ * @param {number[]} bills
+ * @return {boolean}
+ */
+var lemonadeChange = function(bills) {
+  let fives = 0;
+  let tens = 0;
+
+  for (const bill of bills) {
+    if (bill === 5) {
+      fives++;
+    } else if (bill === 10) {
+      if (fives === 0) return false;
+      fives--;
+      tens++;
+    } else {
+      if (tens > 0 && fives > 0) {
+        tens--;
+        fives--;
+      } else if (fives >= 3) {
+        fives -= 3;
+      } else {
+        return false;
+      }
+    }
+  }
+
+  return true;
+};