Update Solution2.rs

Author: yanglbme

solution/0200-0299/0215.Kth Largest Element in an Array/Solution2.rs

@@ -1,28 +1,14 @@
-use rand::Rng;
+use std::collections::BinaryHeap;
 
 impl Solution {
-    pub fn find_kth_largest(mut nums: Vec<i32>, k: i32) -> i32 {
-        let k = k as usize;
-        let n = nums.len();
-        let mut l = 0;
-        let mut r = n;
-        while l <= k - 1 && l < r {
-            nums.swap(l, rand::thread_rng().gen_range(l, r));
-            let num = nums[l];
-            let mut mark = l;
-            for i in l..r {
-                if nums[i] > num {
-                    mark += 1;
-                    nums.swap(i, mark);
-                }
-            }
-            nums.swap(l, mark);
-            if mark + 1 <= k {
-                l = mark + 1;
-            } else {
-                r = mark;
+    pub fn find_kth_largest(nums: Vec<i32>, k: i32) -> i32 {
+        let mut minQ = BinaryHeap::new();
+        for &x in nums.iter() {
+            minQ.push(-x);
+            if minQ.len() > k as usize {
+                minQ.pop();
             }
         }
-        nums[k - 1]
+        -minQ.peek().unwrap()
     }
 }