leetcode

commit 308a71e413c0fabf54727efaf5befc77d72fb362
parent d3c844ce2aef16dbc9fe26fce617f68a1cb1a2a4
Author: Jack Sangdahl <jack@pngu.org>
Date:   Wed, 31 Dec 2025 21:35:25 -0700

66. plus one

Diffstat:
A
plus_one.c
 | 
49
+++++++++++++++++++++++++++++++++++++++++++++++++
A
plus_one.py
 | 
30
++++++++++++++++++++++++++++++

2 files changed, 79 insertions(+), 0 deletions(-)
diff --git a/plus_one.c b/plus_one.c
@@ -0,0 +1,49 @@
+// 66. Plus One
+#include "leetcode.h"
+
+/*
+ * you are given a large integer represented as an integer array 'digits', where
+ * each 'digits[i]' is the i'th digit of thee integer. the digits are ordered
+ * from most significant to least signifcant in left to right order. the large
+ * does not contain any leading zeros. increment the large integer by one and
+ * return the resulting  array of digits.
+ */
+
+int *plusOne(int *digits, int digitsSize, int *returnSize) {
+  for (int i = digitsSize - 1; i >= 0; i--) {
+    if (digits[i] < 9) {
+      digits[i]++;
+      *returnSize = digitsSize;
+      return digits;
+    }
+    digits[i] = 0;
+  }
+  int *ans = (int *)malloc((digitsSize + 1) * sizeof(int));
+  ans[0] = 1;
+  for (int i = 1; i <= digitsSize; i++)
+    ans[i] = 0;
+  *returnSize = digitsSize + 1;
+  return ans;
+}
+
+int main() {
+  int d1[] = {1, 2, 3}, d2[] = {4, 3, 2, 1}, d3[] = {9};
+  int rs1, *po1 = plusOne(d1, ARRAY_SIZE(d1), &rs1);
+  int rs2, *po2 = plusOne(d2, ARRAY_SIZE(d2), &rs2);
+  int rs3, *po3 = plusOne(d3, ARRAY_SIZE(d3), &rs3);
+  for (int i = 0; i < rs1; i++)
+    printf("%d ", po1[i]); // expect: 1 2 4
+  printf("\n");
+  for (int i = 0; i < rs2; i++)
+    printf("%d ", po2[i]); // expect: 4 3 2 2
+  printf("\n");
+  for (int i = 0; i < rs3; i++)
+    printf("%d ", po3[i]); // expect: 1 0
+  printf("\n");
+  if (po1)
+    free(po1);
+  if (po2)
+    free(po2);
+  if (po3)
+    free(po3);
+}
diff --git a/plus_one.py b/plus_one.py
@@ -0,0 +1,30 @@
+# 66. Plus One
+
+"""
+you are given a large integer represented as an integer array 'digits', where
+each 'digits[i]' is the i'th digit of thee integer. the digits are ordered
+from most significant to least signifcant in left to right order. the large
+does not contain any leading zeros. increment the large integer by one and
+return the resulting  array of digits.
+"""
+
+
+class Solution(object):
+    def plusOne(self, digits):
+        """
+        :type digits: List[int]
+        :rtype: List[int]
+        """
+        for i in range(len(digits) - 1, -1, -1):
+            if digits[i] < 9:
+                digits[i] += 1
+                return digits
+            digits[i] = 0
+        return [1] + digits
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.plusOne(digits=[1, 2, 3]))
+    print(obj.plusOne(digits=[4, 3, 2, 1]))
+    print(obj.plusOne(digits=[9]))