2958. 最多 K 个重复元素的最长子数组

src/main.rs

@@ -1,34 +1,26 @@
+use std::collections::HashMap;
+
 mod arr;
 struct Solution {}
 impl Solution {
-    pub fn count_majority_subarrays(nums: Vec<i32>, target: i32) -> i64 {
-        let mut arr: Vec<i32> = vec![0; nums.len() + 1];
-        for i in 0..nums.len() {
-            arr[i + 1] = arr[i] + if nums[i] == target { 1 } else { -1 };
-        }
-        // [-n, n] -> [0, 2n]
-        let n = nums.len() as i32;
-        let mut pre = vec![0; nums.len() * 2 + 1];
-        let mut presum = 0;
+    pub fn max_subarray_length(nums: Vec<i32>, k: i32) -> i32 {
+        let mut mp = HashMap::new();
+        let mut l: i64 = -1;
         let mut ans = 0;
-        println!("{:?}", arr);
         for r in 0..nums.len() {
-            pre[(arr[r] + n) as usize] += 1;
-            if arr[r + 1] > arr[r] {
-                presum += pre[(arr[r] + n) as usize];
-            } else {
-                presum = (presum - pre[(arr[r + 1] + n) as usize]).max(0);
+            *mp.entry(nums[r]).or_insert(0) += 1;
+            while *mp.get(&nums[r]).unwrap() > k {
+                l += 1;
+                *mp.get_mut(&nums[l as usize]).unwrap() -= 1
             }
-            ans += presum;
+            ans = ans.max(r as i32 - l as i32);
         }
         ans
     }
 }
 fn main() {
-    //    1   2   2   3
-    //  0  -1   0   1   0
     println!(
         "{:?}",
-        Solution::count_majority_subarrays(vec![1, 2, 2, 3], 2)
+        Solution::max_subarray_length(vec![1, 2, 3, 1, 2, 3, 1, 2], 2)
     );
 }