Problems > Flips to Alternate

Flips to Alternate

Difficulty: 1200 2000 ms 128 MB

strings greedy

You may flip individual characters of a binary string. What is the minimum number of flips to make it alternating (no two adjacent characters equal)?

Input: one line with a binary string.

Output: the minimum number of flips.

Constraints:

  • 1 ≤ |S| ≤ 105

Sample Tests

Input 1
0100
Output 1
1
Input 2
10
Output 2
0

Read the Editorial

Discussion (opens after you solve — no spoilers before)

No comments yet.

Submit Your Solution

Log in or create a free account to run and submit code.