dialy

Author: Zanger67

my-submissions/m1151 v1.py

@@ -0,0 +1,16 @@
+class Solution:
+    def minSwaps(self, data: List[int]) -> int:
+        # convert data into a prefix sum starting at zero
+        running_total = 0
+        for i in range(len(data)) :
+            data[i], running_total = running_total, running_total + data[i]
+        data.append(running_total)
+
+        tot_ones = data[-1]
+
+        # Find window of size tot_ones with the most ones already there
+        output = 0
+        for i in range(tot_ones, len(data)) :
+            output = max(output, data[i] - data[i - tot_ones])
+
+        return tot_ones - output

my-submissions/m1151 v2.py

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+class Solution:
+    def minSwaps(self, data: List[int]) -> int:
+        # convert data into a prefix sum starting at zero
+        running_total = 0
+        for i in range(len(data)) :
+            data[i], running_total = running_total, running_total + data[i]
+        data.append(running_total)
+
+        tot_ones = data[-1]
+
+        return min(tot_ones - (data[i] - data[i - tot_ones]) for i in range(tot_ones, len(data)))

my-submissions/m1151 v3.py

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+class Solution:
+    def minSwaps(self, data: List[int]) -> int:
+        data = [0] + list(accumulate(data))
+        tot_ones = data[-1]
+        return tot_ones - max(data[i + tot_ones] - data[i] for i in range(len(data) - tot_ones))

my-submissions/m1151.md

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+## V1
+
+Initial decently performing prefix sum + sliding window attempt.
+
+## V2
+
+Optimized window finding by using a max function
+
+## V3
+
+Optimized further (though at the expense of no longer being $O(1)$ space) by using `itertools.accumulate` to get the prefix sum.
+
+**Note**: Built in functions are almost always more efficiently implemented due to them falling back on `C`.