using the windows() iter methods is slow

max_k_sum_pairs/src/main.rs

@@ -13,9 +13,7 @@ fn foo(nums: &mut [i32], k: i32) -> i32 {
     let mut right = nums.len() - 1;
 
     while left < right {
-        let lv = nums[left];
+        let sum = nums[left] + nums[right];
-        let rv = nums[right];
-        let sum = lv + rv;
         if sum < k {
             left += 1;
         } else if sum > k {

max_vowels_in_substring_k/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "max_vowels_in_substring_k"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

max_vowels_in_substring_k/src/main.rs

@@ -0,0 +1,29 @@
+fn main() {
+    //dbg!(m("aennnnnnnnnnnnniii".to_string(), 4));
+    //dbg!(m("abciiidef".to_string(), 3));
+    dbg!(m("leetcode".to_string(), 3));
+}
+
+fn m(s: String, k: i32) -> i32 {
+    let mut cur: i32 = s.chars().take(k as usize).map(is_vowel).sum();
+    let cur = &mut cur;
+    let mut max = *cur;
+    let max = &mut max;
+    let add = s.chars().skip(k as usize);
+    let mut sub = s.chars();
+    for c in add {
+        let s = sub.next().unwrap();
+        *cur -= is_vowel(s);
+        *cur += is_vowel(c);
+        *max = *max.max(cur);
+    }
+
+    *max
+}
+
+fn is_vowel(c: char) -> i32 {
+    match c {
+        'e' | 'i' | 'o' | 'u' | 'a' => 1,
+        _ => 0,
+    }
+}