feat: resolved

Author: jtr109

maximum_gap/src/lib.rs

@@ -1,7 +1,38 @@
 pub struct Solution {}
 
 impl Solution {
-    pub fn maximum_gap(nums: Vec<i32>) -> i32 {}
+    pub fn maximum_gap(nums: Vec<i32>) -> i32 {
+        /*!
+        使用 bucket sort 实现
+        思路：控制每个 bucket 的范围小于最小值和最大值之间元素数量不变，但是等间隔时的间隔范围
+        判断 buckets 之间前一个 bucket 的最大值和后一个 bucket 的最小值之差，取结果中的最大值
+         */
+        if nums.len() < 2 {
+            return 0;
+        }
+
+        let lo = nums.iter().min().unwrap();
+        let hi = nums.iter().max().unwrap();
+        if lo == hi {
+            return 0;
+        }
+
+        let mut buckets = vec![vec![]; nums.len() + 1];
+        for n in nums.iter() {
+            let index = (n - lo) as usize * (nums.len() - 1) / (hi - lo) as usize;
+            buckets[index].push(*n);
+        }
+        let pairs = buckets
+            .iter()
+            .filter(|b| b.len() > 0)
+            .map(|b| (*b.iter().min().unwrap(), *b.iter().max().unwrap()))
+            .collect::<Vec<(i32, i32)>>();
+        let mut max_gap = 0;
+        for i in 0..pairs.len() - 1 {
+            max_gap = max_gap.max(pairs[i + 1].0 - pairs[i].1);
+        }
+        max_gap
+    }
 }
 
 #[cfg(test)]
@@ -25,4 +56,25 @@ mod tests {
         let expected = 0;
         it_works(nums, expected);
     }
+
+    #[test]
+    fn submission_test_1() {
+        let nums = vec![1, 10000000];
+        let expected = 9999999;
+        it_works(nums, expected);
+    }
+
+    #[test]
+    fn submission_test_2() {
+        let nums = vec![1, 1, 1, 1];
+        let expected = 0;
+        it_works(nums, expected);
+    }
+
+    #[test]
+    fn submission_test_3() {
+        let nums = vec![1, 1, 1, 1, 1, 5, 5, 5, 5, 5];
+        let expected = 4;
+        it_works(nums, expected);
+    }
 }