Create 0875-koko-eating-bananas.rs

rust/0875-koko-eating-bananas.rs

@@ -0,0 +1,26 @@
+use std::cmp::Ordering::{Equal, Less, Greater};
+
+impl Solution {
+    pub fn min_eating_speed(piles: Vec<i32>, h: i32) -> i32 {
+        let max_piles = *piles.iter().max().unwrap() as usize;
+        let (mut l, mut r) = (1, max_piles);
+        let mut k = max_piles;
+
+        while l <= r {
+            let m = l + (r - l) / 2;
+            let hrs: usize = piles.iter()
+                .map(|&num_bananas| ((num_bananas - 1) as usize / m) + 1)
+                .sum();
+
+            match hrs.cmp(&(h as usize)) {
+                Less | Equal => {
+                    k = k.min(m);
+                    r = m - 1;
+                },
+                Greater => l = m + 1, 
+            }
+        }
+
+        k as i32
+    }
+}