leetcode

commit 81420085b4cc32b8aed587a69fda849214690fde
parent 1fa352f782e5c1352e7824a927238e06eddd2604
Author: Jack Sangdahl <jack@pngu.org>
Date:   Sat,  7 Mar 2026 19:57:51 -0700

1980. find unique binary string

Diffstat:
M
find_unique_binary_str.c
 | 
30
++++++++++++++++++------------
M
find_unique_binary_str.py
 | 
11
++++-------

2 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/find_unique_binary_str.c b/find_unique_binary_str.c
@@ -9,20 +9,26 @@
 
 char *findDifferentBinaryString(char **nums, int numsSize) {
   char *ans = (char *)malloc((numsSize + 1) * sizeof(char));
-  int j = 0;
   for (int i = 0; i < numsSize; i++)
-    ans[j++] = nums[i][i] == '0' ? '1' : '0';
-  ans[j] = '\0';
-  return j ? ans : "";
+    ans[i] = nums[i][i] == '0' ? '1' : '0';
+  ans[numsSize] = '\0';
+  return ans;
 }
 
 int main() {
-  char *n1[] = {"01", "10"}, *n2[] = {"00", "01"},
-       *n3[] = {"111", "011", "001"};
-  printf("%s\n",
-         findDifferentBinaryString((char **)n1, ARRAY_SIZE(n1))); // expect: 11
-  printf("%s\n",
-         findDifferentBinaryString((char **)n2, ARRAY_SIZE(n2))); // expect: 11
-  printf("%s\n",
-         findDifferentBinaryString((char **)n3, ARRAY_SIZE(n3))); // expect: 101
+  char *n1[] = {"01", "10"};
+  char *n2[] = {"00", "01"};
+  char *n3[] = {"111", "011", "001"};
+  char *r1 = findDifferentBinaryString((char **)n1, ARRAY_SIZE(n1));
+  char *r2 = findDifferentBinaryString((char **)n2, ARRAY_SIZE(n2));
+  char *r3 = findDifferentBinaryString((char **)n3, ARRAY_SIZE(n3));
+  printf("%s\n", r1); // expect: 11
+  assert(!strcmp(r1, "11"));
+  printf("%s\n", r2); // expect: 10
+  assert(!strcmp(r2, "10"));
+  printf("%s\n", r3); // expect: 000
+  assert(!strcmp(r3, "000"));
+  free(r1);
+  free(r2);
+  free(r3);
 }
diff --git a/find_unique_binary_str.py b/find_unique_binary_str.py
@@ -1,4 +1,5 @@
 # 1980. Find Unique Binary String
+from typing import List
 
 """
 given an array of strings 'nums' containing 'n' unique binary strings each of
@@ -7,13 +8,9 @@ length 'n', return a binary string of length 'n' that does not appear in
 """
 
 
-class Solution(object):
-    def findDifferentBinaryString(self, nums):
-        """
-        :type nums: List[str]
-        :rtype: str
-        """
-        return "".join(["1" if num[i] == "0" else "0" for i, num in enumerate(nums)])
+class Solution:
+    def findDifferentBinaryString(self, nums: List[str]) -> str:
+        return "".join(["1" if n[i] == "0" else "0" for i, n in enumerate(nums)])
 
 
 if __name__ == "__main__":