Minimum swaps to group all 1s together

Array Sliding Window

61.2% acceptance

Mar 31, 2026

1279

Given a binary array data, return the minimum number of swaps required to group all 1’s present in the array together in any place in the array.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn min_swaps(data: Vec<i32>) -> i32 {
    let ones: i32 = data.iter().sum();
    if ones <= 1 {
      return 0;
    }
    let k = ones as usize;
    let mut zeros_in_window: i32 = data[..k].iter().filter(|&&x| x == 0).count() as i32;
    let mut min_swaps = zeros_in_window;
    for i in k..data.len() {
      zeros_in_window += (1 - data[i]);
      zeros_in_window -= (1 - data[i - k]);
      min_swaps = min_swaps.min(zeros_in_window);
    }
    min_swaps
  }
}