leetcode

commit c21b21782861dde4d3d1744b91945addf8730c50
parent e2463525ffdacdfa6af3f1c7b9c29e248f695eff
Author: Jack Sangdahl <jack@pngu.org>
Date:   Fri,  5 Dec 2025 09:31:15 +0100

432. count partitions with even sum difference

Diffstat:
A
count_partition_even_sum_diff.c
 | 
25
+++++++++++++++++++++++++
A
count_partition_even_sum_diff.py
 | 
29
+++++++++++++++++++++++++++++

2 files changed, 54 insertions(+), 0 deletions(-)
diff --git a/count_partition_even_sum_diff.c b/count_partition_even_sum_diff.c
@@ -0,0 +1,25 @@
+// 3432. Count Partitions with Even Sum Difference
+#include "leetcode.h"
+
+/*
+ * you are given an integer array 'nums' of length 'n'. a partition is defined
+ * as an index 'i' where '0 <= i < n - 1', splitting the array into two
+ * non-empty subarrays such that left subarray contains indices '[0, i]' and the
+ * right subarray contains indices '[i + 1, n - 1]'. return the number of
+ * partitions where the difference between the sum of the left and right
+ * subarrays is even.
+ */
+
+int countPartitions(int *nums, int numsSize) {
+  int n = 1;
+  for (int i = 0; i < numsSize; i++)
+    n ^= nums[i];
+  return (n & 1) * (numsSize - 1);
+}
+
+int main() {
+  int n1[] = {10, 10, 3, 7, 6}, n2[] = {1, 2, 2}, n3[] = {2, 4, 6, 8};
+  printf("%d\n", countPartitions(n1, ARRAY_SIZE(n1))); // expect: 4
+  printf("%d\n", countPartitions(n2, ARRAY_SIZE(n2))); // expect: 0
+  printf("%d\n", countPartitions(n3, ARRAY_SIZE(n3))); // expect: 3
+}
diff --git a/count_partition_even_sum_diff.py b/count_partition_even_sum_diff.py
@@ -0,0 +1,29 @@
+# 432. Count Partitions with Even Sum Difference
+
+"""
+you are given an integer array 'nums' of length 'n'. a partition is defined
+as an index 'i' where '0 <= i < n - 1', splitting the array into two
+non-empty subarrays such that left subarray contains indices '[0, i]' and the
+right subarray contains indices '[i + 1, n - 1]'. return the number of
+partitions where the difference between the sum of the left and right
+subarrays is even.
+"""
+
+
+class Solution(object):
+    def countPartitions(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        parity = nums.pop() & 1
+        for i in nums:
+            parity ^= i & 1
+        return (parity ^ 1) * len(nums)
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.countPartitions(nums=[10, 10, 3, 7, 6]))
+    print(obj.countPartitions(nums=[1, 2, 2]))
+    print(obj.countPartitions(nums=[2, 4, 6, 8]))