feat: add solutions to lc problem: No.1438 (#2575)

No.1438.Longest Continuous Subarray With Absolute Diff Less Than or
Equal to Limit

Author: yanglbme

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/README.md

@@ -1,25 +1,18 @@
 func longestSubarray(nums []int, limit int) (ans int) {
-	tm := treemap.NewWithIntComparator()
-	j := 0
-	for i, v := range nums {
-		if x, ok := tm.Get(v); ok {
-			tm.Put(v, x.(int)+1)
+	merge := func(st *redblacktree.Tree[int, int], x, v int) {
+		c, _ := st.Get(x)
+		if c+v == 0 {
+			st.Remove(x)
 		} else {
-			tm.Put(v, 1)
+			st.Put(x, c+v)
 		}
-		for {
-			a, _ := tm.Min()
-			b, _ := tm.Max()
-			if b.(int)-a.(int) > limit {
-				if x, _ := tm.Get(nums[j]); x.(int) == 1 {
-					tm.Remove(nums[j])
-				} else {
-					tm.Put(nums[j], x.(int)-1)
-				}
-				j++
-			} else {
-				break
-			}
+	}
+	st := redblacktree.New[int, int]()
+	j := 0
+	for i, x := range nums {
+		merge(st, x, 1)
+		for ; st.Right().Key-st.Left().Key > limit; j++ {
+			merge(st, nums[j], -1)
 		}
 		ans = max(ans, i-j+1)
 	}

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/README_EN.md

@@ -1,15 +1,13 @@
 class Solution {
     public int longestSubarray(int[] nums, int limit) {
         TreeMap<Integer, Integer> tm = new TreeMap<>();
-        int ans = 0, j = 0;
-        for (int i = 0; i < nums.length; ++i) {
-            tm.put(nums[i], tm.getOrDefault(nums[i], 0) + 1);
-            while (tm.lastKey() - tm.firstKey() > limit) {
-                tm.put(nums[j], tm.get(nums[j]) - 1);
-                if (tm.get(nums[j]) == 0) {
+        int ans = 0;
+        for (int i = 0, j = 0; i < nums.length; ++i) {
+            tm.merge(nums[i], 1, Integer::sum);
+            for (; tm.lastKey() - tm.firstKey() > limit; ++j) {
+                if (tm.merge(nums[j], -1, Integer::sum) == 0) {
                     tm.remove(nums[j]);
                 }
-                ++j;
             }
             ans = Math.max(ans, i - j + 1);
         }

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution.go

@@ -5,8 +5,8 @@ class Solution:
     def longestSubarray(self, nums: List[int], limit: int) -> int:
         sl = SortedList()
         ans = j = 0
-        for i, v in enumerate(nums):
-            sl.add(v)
+        for i, x in enumerate(nums):
+            sl.add(x)
             while sl[-1] - sl[0] > limit:
                 sl.remove(nums[j])
                 j += 1

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution.java

@@ -4,7 +4,7 @@ function longestSubarray(nums: number[], limit: number): number {
     let j = 0;
     for (let i = 0; i < nums.length; ++i) {
         ts.add(nums[i]);
-        while (ts.last() - ts.first() > limit) {
+        while (ts.last()! - ts.first()! > limit) {
             ts.delete(nums[j++]);
         }
         ans = Math.max(ans, i - j + 1);

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution.py

@@ -0,0 +1,39 @@
+class Solution {
+public:
+    int longestSubarray(vector<int>& nums, int limit) {
+        auto check = [&](int k) {
+            deque<int> min_q;
+            deque<int> max_q;
+            for (int i = 0; i < nums.size(); ++i) {
+                if (!min_q.empty() && i - min_q.front() + 1 > k) {
+                    min_q.pop_front();
+                }
+                if (!max_q.empty() && i - max_q.front() + 1 > k) {
+                    max_q.pop_front();
+                }
+                while (!min_q.empty() && nums[min_q.back()] >= nums[i]) {
+                    min_q.pop_back();
+                }
+                while (!max_q.empty() && nums[max_q.back()] <= nums[i]) {
+                    max_q.pop_back();
+                }
+                min_q.push_back(i);
+                max_q.push_back(i);
+                if (i >= k - 1 && nums[max_q.front()] - nums[min_q.front()] <= limit) {
+                    return true;
+                }
+            }
+            return false;
+        };
+        int l = 1, r = nums.size();
+        while (l < r) {
+            int mid = (l + r + 1) >> 1;
+            if (check(mid)) {
+                l = mid;
+            } else {
+                r = mid - 1;
+            }
+        }
+        return l;
+    }
+};

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution.ts

@@ -0,0 +1,94 @@
+func longestSubarray(nums []int, limit int) int {
+	l, r := 0, len(nums)
+	check := func(k int) bool {
+		minq := Deque{}
+		maxq := Deque{}
+		for i, x := range nums {
+			for !minq.Empty() && i-minq.Front()+1 > k {
+				minq.PopFront()
+			}
+			for !maxq.Empty() && i-maxq.Front()+1 > k {
+				maxq.PopFront()
+			}
+			for !minq.Empty() && nums[minq.Back()] >= x {
+				minq.PopBack()
+			}
+			for !maxq.Empty() && nums[maxq.Back()] <= x {
+				maxq.PopBack()
+			}
+			minq.PushBack(i)
+			maxq.PushBack(i)
+			if i >= k-1 && nums[maxq.Front()]-nums[minq.Front()] <= limit {
+				return true
+			}
+		}
+		return false
+	}
+	for l < r {
+		mid := (l + r + 1) >> 1
+		if check(mid) {
+			l = mid
+		} else {
+			r = mid - 1
+		}
+	}
+	return l
+}
+
+// template
+type Deque struct{ l, r []int }
+
+func (q Deque) Empty() bool {
+	return len(q.l) == 0 && len(q.r) == 0
+}
+
+func (q Deque) Size() int {
+	return len(q.l) + len(q.r)
+}
+
+func (q *Deque) PushFront(v int) {
+	q.l = append(q.l, v)
+}
+
+func (q *Deque) PushBack(v int) {
+	q.r = append(q.r, v)
+}
+
+func (q *Deque) PopFront() (v int) {
+	if len(q.l) > 0 {
+		q.l, v = q.l[:len(q.l)-1], q.l[len(q.l)-1]
+	} else {
+		v, q.r = q.r[0], q.r[1:]
+	}
+	return
+}
+
+func (q *Deque) PopBack() (v int) {
+	if len(q.r) > 0 {
+		q.r, v = q.r[:len(q.r)-1], q.r[len(q.r)-1]
+	} else {
+		v, q.l = q.l[0], q.l[1:]
+	}
+	return
+}
+
+func (q Deque) Front() int {
+	if len(q.l) > 0 {
+		return q.l[len(q.l)-1]
+	}
+	return q.r[0]
+}
+
+func (q Deque) Back() int {
+	if len(q.r) > 0 {
+		return q.r[len(q.r)-1]
+	}
+	return q.l[0]
+}
+
+func (q Deque) Get(i int) int {
+	if i < len(q.l) {
+		return q.l[len(q.l)-1-i]
+	}
+	return q.r[i-len(q.l)]
+}

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution2.cpp

@@ -0,0 +1,44 @@
+class Solution {
+    private int[] nums;
+    private int limit;
+
+    public int longestSubarray(int[] nums, int limit) {
+        this.nums = nums;
+        this.limit = limit;
+        int l = 1, r = nums.length;
+        while (l < r) {
+            int mid = (l + r + 1) >> 1;
+            if (check(mid)) {
+                l = mid;
+            } else {
+                r = mid - 1;
+            }
+        }
+        return l;
+    }
+
+    private boolean check(int k) {
+        Deque<Integer> minQ = new ArrayDeque<>();
+        Deque<Integer> maxQ = new ArrayDeque<>();
+        for (int i = 0; i < nums.length; ++i) {
+            if (!minQ.isEmpty() && i - minQ.peekFirst() + 1 > k) {
+                minQ.pollFirst();
+            }
+            if (!maxQ.isEmpty() && i - maxQ.peekFirst() + 1 > k) {
+                maxQ.pollFirst();
+            }
+            while (!minQ.isEmpty() && nums[minQ.peekLast()] >= nums[i]) {
+                minQ.pollLast();
+            }
+            while (!maxQ.isEmpty() && nums[maxQ.peekLast()] <= nums[i]) {
+                maxQ.pollLast();
+            }
+            minQ.offer(i);
+            maxQ.offer(i);
+            if (i >= k - 1 && nums[maxQ.peekFirst()] - nums[minQ.peekFirst()] <= limit) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

solution/1400-1499/1438.Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit/Solution2.go

@@ -0,0 +1,28 @@
+class Solution:
+    def longestSubarray(self, nums: List[int], limit: int) -> int:
+        def check(k: int) -> bool:
+            min_q = deque()
+            max_q = deque()
+            for i, x in enumerate(nums):
+                if min_q and i - min_q[0] + 1 > k:
+                    min_q.popleft()
+                if max_q and i - max_q[0] + 1 > k:
+                    max_q.popleft()
+                while min_q and nums[min_q[-1]] >= x:
+                    min_q.pop()
+                while max_q and nums[max_q[-1]] <= x:
+                    max_q.pop()
+                min_q.append(i)
+                max_q.append(i)
+                if i >= k - 1 and nums[max_q[0]] - nums[min_q[0]] <= limit:
+                    return True
+            return False
+
+        l, r = 1, len(nums)
+        while l < r:
+            mid = (l + r + 1) >> 1
+            if check(mid):
+                l = mid
+            else:
+                r = mid - 1
+        return l