rearranging fruit is an example of greedy algorithm

dynamic_programming/coin_change_II.py

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+from typing import List
+
+class Solution:
+    def change(self, amount: int, coins: List[int]) -> int:
+        cache = {}
+        def dfs(i,a):
+            if a == amount:
+                return 1
+            if a > amount:
+                return 0
+            if i == len(coins):
+                return 0
+            if (i,a) in cache:
+                return cache[(i,a)]
+            cache[(i,a)] = dfs(i,a + coins[i]) +dfs(i+1, a)
+            return cache[(i,a)]
+        return dfs(0,0)
+
+sol = Solution()
+# for example
+print(sol.change(5, [1,2,5]))  # Output: 4

greedy_methods/rearranging_fruits.py

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+class Solution:
+    def minCost(self, basket1: List[int], basket2: List[int]) -> int:
+        n = len(basket1)
+        freq = defaultdict(int)
+        mn = float('inf')
+        for i in range(n):
+            freq[basket1[i]] += 1
+            freq[basket2[i]] -= 1
+            mn = min(mn, basket1[i], basket2[i])
+
+        to_swap = []
+        for j,k in freq.items():
+            if k % 2 != 0:
+                return -1
+            to_swap += [j] * (abs(k) // 2)
+
+        to_swap.sort()
+        res = 0
+        for i in range(len(to_swap) // 2):
+            res += min(to_swap[i], 2 * mn)
+
+        return res