From eceea49417cf3048b8a2ea474bbc487620bbc924 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9rgio=20Salgado?= <sergiodiassalgado@gmail.com>
Date: Fri, 15 Oct 2021 14:59:16 +0100
Subject: [PATCH] fix: makeChangeDynamic

---
 lib/bill-math.js | 96 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 68 insertions(+), 28 deletions(-)

diff --git a/lib/bill-math.js b/lib/bill-math.js
index b665840a..960868ef 100644
--- a/lib/bill-math.js
+++ b/lib/bill-math.js
@@ -48,37 +48,77 @@ function makeChangeDuo (cassettes, amount) {
 }
 
 function makeChangeDynamic (cassettes, amount) {
-  const cassetteMap = _.map(cassettes, it => ({
-    denomination: it.denomination
-  }))
+  while (_.size(cassettes) < 4) {
+    cassettes.push({ denomination: 0, count: 0 })
+  }
+
+  const solutions = []
   const amountNum = amount.toNumber()
-
-  const sortedCassettes = _.orderBy(cassetteMap, ['denomination'], ['desc'])
-
-  const finalDist = []
-
-  let mutableAmount = _.clone(amountNum)
-
-  while(mutableAmount >= 0) {
-    _.each(sortedCassettes, it => {
-      if (mutableAmount === 0) {
-        finalDist.push({ provisioned: 0, denomination: it.denomination, id: uuid.v4() })
-        return
+  for (let i = 0; i * cassettes[0].denomination <= amountNum; i++) {
+    for (
+      let j = 0;
+      i * cassettes[0].denomination + j * cassettes[1].denomination <=
+      amountNum;
+      j++
+    ) {
+      for (
+        let k = 0;
+        i * cassettes[0].denomination +
+          j * cassettes[1].denomination +
+          k * cassettes[2].denomination <=
+        amountNum;
+        k++
+      ) {
+        for (
+          let l = 0;
+          i * cassettes[0].denomination +
+            j * cassettes[1].denomination +
+            k * cassettes[2].denomination +
+            l * cassettes[3].denomination <=
+          amountNum;
+          l++
+        ) {
+          if (
+            i * cassettes[0].denomination +
+              j * cassettes[1].denomination +
+              k * cassettes[2].denomination +
+              l * cassettes[3].denomination ===
+              amountNum &&
+            i <= cassettes[0].count &&
+            j <= cassettes[1].count &&
+            k <= cassettes[2].count &&
+            l <= cassettes[3].count && i > 0 && j > 0 && k > 0 && l > 0
+          ) {
+            solutions.push([
+              {
+                provisioned: i,
+                denomination: cassettes[0].denomination,
+                id: uuid.v4()
+              },
+              {
+                provisioned: j,
+                denomination: cassettes[1].denomination,
+                id: uuid.v4()
+              },
+              {
+                provisioned: k,
+                denomination: cassettes[2].denomination,
+                id: uuid.v4()
+              },
+              {
+                provisioned: l,
+                denomination: cassettes[3].denomination,
+                id: uuid.v4()
+              }
+            ])
+          }
+        }
       }
-
-      const remainder = mutableAmount % it.denomination
-      const amountToSub = mutableAmount - remainder
-      const numberOfBills = amountToSub / it.denomination
-      mutableAmount -= amountToSub
-
-      finalDist.push({ provisioned: numberOfBills, denomination: it.denomination, id: uuid.v4() })
-      return
-    })
-
-    if (mutableAmount === 0) {
-      break
     }
   }
 
-  return finalDist
+  const sortedSolutions = _.sortBy(solutions, it => {
+    _.reduce(it, (acc, value) => acc + value.provisioned, 0)
+  })
+  return _.head(sortedSolutions)
 }