# 05.03.2026 [1758. Minimum Changes To Make Alternating Binary String]
Min flips to make bits alterating #easy
05.03.2026
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Problem TLDR
Min flips to make bits alterating #easy
Intuition
Check two targets: 01-type and 10-type.
Approach
we can count a balance: |balance| = |correct-wrong|, L=C+W, L-|B|=(C+W)-(C-W)=2W, W=(L-|B|)/2
(i + s[i]) %2 is an even-odd match
Complexity
Time complexity: $$O(n)$$
Space complexity: $$O(1)$$
Code
// 16ms
fun minOperations(s: String) = s.length/2-
abs(s.indices.sumOf { 1-2*((it+s[it].code)%2) })/2
// 0ms
pub fn min_operations(s: String) -> i32 {
s.len()as i32/2 - s.bytes().enumerate().map(|(i,b)|(1-2*((i as u8^b)&1)as i32)).sum::<i32>().abs()/2
}