leetcode

commit c97ecf064b7843f9abe529b0a6e0638ec103ddd9
parent 39db6fb1c89596bba2efd036de5b4834b0f38642
Author: Jack Sangdahl <jack@pngu.org>
Date:   Fri,  6 Feb 2026 21:49:57 -0700

1653. minimum deletions to make string balanced

Diffstat:
M
min_deletions_balance_str.c
 | 
23
+++++++++++++----------
M
min_deletions_balance_str.py
 | 
13
++++++-------

2 files changed, 19 insertions(+), 17 deletions(-)
diff --git a/min_deletions_balance_str.c b/min_deletions_balance_str.c
@@ -10,20 +10,23 @@
  */
 
 int minimumDeletions(char *s) {
-  int cnt = 0, ans = 0;
-  for (int i = 0; s[i] != '\0'; i++) {
-    if (s[i] == 'b') {
+  int cnt = 0, del = 0;
+  while (*s) {
+    if (*s == 'a')
+      del = fmin(++del, cnt);
+    else
       cnt++;
-    } else if (cnt) {
-      ans++;
-      cnt--;
-    }
+    *s++;
   }
-  return ans;
+  return del;
 }
 
 int main() {
   char *s1 = "aababbab", *s2 = "bbaaaaabb";
-  printf("%d\n", minimumDeletions(s1)); // expect: 2
-  printf("%d\n", minimumDeletions(s2)); // expect: 2
+  int r1 = minimumDeletions(s1);
+  int r2 = minimumDeletions(s2);
+  printf("%d\n", r1); // expect: 2
+  assert(r1 == 2);
+  printf("%d\n", r1); // expect: 2
+  assert(r2 == 2);
 }
diff --git a/min_deletions_balance_str.py b/min_deletions_balance_str.py
@@ -15,14 +15,13 @@ class Solution(object):
         :type s: str
         :rtype: int
         """
-        a, b, cnt = s.count("a"), 0, len(s)
-        for c in s:
-            if c == "b":
-                cnt = min(cnt, a + b)
-                b += 1
+        cnt, rem = 0, 0
+        for i in s:
+            if i == "a":
+                rem = min(rem + 1, cnt)
             else:
-                a -= 1
-        return min(cnt, b)
+                cnt += 1
+        return rem
 
 
 if __name__ == "__main__":