[Sync Iteration] python/change/1

solutions/python/change/1/change.py

@@ -0,0 +1,26 @@
+def find_fewest_coins(coins, target):
+    if target == 0:
+        return []
+    if target < 0:
+        raise ValueError("target can't be negative")
+    dp = [float('inf')] * (target + 1)
+    dp[0] = 0
+    backtrack = [-1] * (target + 1)
+    for i in range(1, target + 1):
+        for c in coins:
+            if i - c >= 0 and dp[i - c] + 1 < dp[i]:
+                dp[i] = dp[i - c] + 1
+                backtrack[i] = c
+        #print(backtrack)
+    curr = target
+    used_coins = []
+    while curr > 0:
+        coin = backtrack[curr]
+        if coin == -1:
+            break  # no solution
+        used_coins.append(coin)
+        curr -= coin
+    if not used_coins:
+        raise ValueError("can't make target with given coins")
+    return used_coins
+#print(find_fewest_coins([1, 5, 10, 21, 25], 0))