Number of student replacements

Array Simulation

86.2% acceptance

Mar 31, 2026

You are given an integer array ranks where ranks[i] represents the rank of the ith student arriving in order. A lower number indicates a better rank. Initially, the first student is selected by default. A replacement occurs when a student with a strictly better rank arrives and replaces the current selection. Return the total number of replacements made.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn total_replacements(ranks: Vec<i32>) -> i32 {
    let mut count = 0;
    let mut best = ranks[0];
    for i in 1..ranks.len() {
      if ranks[i] < best {
        best = ranks[i];
        count += 1;
      }
    }
    count
  }
}