add : Minimum coins program by using GREEDY methods

greedy_methods/minimum_coins.py

@@ -0,0 +1,43 @@
+"""
+Given a list of coin denominations and an amount,
+this program calculates the minimum number of coins needed to make up that amount.
+
+Example :
+coins = [1, 2, 5, 10, 20, 50, 100, 500, 2000],
+amount = 121, 
+The minimum number of coins would be 3 (100 + 20 + 1).
+
+This problem can be solved using the concept of "GREEDY ALGORITHM".
+
+We start with the largest denomination of coins and use as many of those,
+as possible before moving to the next largest denomination.
+This process continues until the entire amount has been made up of coins.
+"""
+
+def min_coins(coins : list[int], amount : int = 0) -> tuple:
+    """
+    >>> min_coins([1, 2, 5, 10, 20, 50, 100, 500, 2000],121)
+    (3, [100, 20, 1])
+    >>> min_coins([1, 2, 5, 10, 20, 50, 100],343)
+    (7, [100, 100, 100, 20, 20, 2, 1])
+    >>> min_coins([1,2,5,10],0)
+    (0, [])
+    """
+    coins.sort(reverse=True)
+    count : int = 0
+    coins_list : list[int] = []
+    for coin in coins:
+        if coin <= amount:
+            while coin <= amount:
+                count += 1
+                coins_list.append(coin)
+                amount -= coin
+
+    return count, coins_list
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()
+
+    print(f"{min_coins([1, 2, 5, 10, 20, 50, 100, 500, 2000],121)}")
+