feat: add solutions to lc problem: No.2208 (#3537)

No.2208.Minimum Operations to Halve Array Sum

Author: yanglbme

solution/2200-2299/2208.Minimum Operations to Halve Array Sum/README.md

@@ -89,14 +89,14 @@ nums 的和减小了 31 - 14.5 = 16.5 ，减小的部分超过了初始数组和
 class Solution:
     def halveArray(self, nums: List[int]) -> int:
         s = sum(nums) / 2
-        h = []
-        for v in nums:
-            heappush(h, -v)
+        pq = []
+        for x in nums:
+            heappush(pq, -x)
         ans = 0
         while s > 0:
-            t = -heappop(h) / 2
+            t = -heappop(pq) / 2
             s -= t
-            heappush(h, -t)
+            heappush(pq, -t)
             ans += 1
         return ans
 ```
@@ -106,18 +106,18 @@ class Solution:
 ```java
 class Solution {
     public int halveArray(int[] nums) {
+        PriorityQueue<Double> pq = new PriorityQueue<>(Collections.reverseOrder());
         double s = 0;
-        PriorityQueue<Double> q = new PriorityQueue<>(Collections.reverseOrder());
-        for (int v : nums) {
-            q.offer(v * 1.0);
-            s += v;
+        for (int x : nums) {
+            s += x;
+            pq.offer((double) x);
         }
         s /= 2.0;
         int ans = 0;
         while (s > 0) {
-            double t = q.poll();
-            s -= t / 2.0;
-            q.offer(t / 2.0);
+            double t = pq.poll() / 2.0;
+            s -= t;
+            pq.offer(t);
             ++ans;
         }
         return ans;
@@ -131,19 +131,19 @@ class Solution {
 class Solution {
 public:
     int halveArray(vector<int>& nums) {
-        priority_queue<double> q;
+        priority_queue<double> pq;
         double s = 0;
-        for (int& v : nums) {
-            s += v;
-            q.push(v);
+        for (int x : nums) {
+            s += x;
+            pq.push((double) x);
         }
         s /= 2.0;
         int ans = 0;
         while (s > 0) {
-            double t = q.top() / 2;
-            q.pop();
+            double t = pq.top() / 2.0;
+            pq.pop();
             s -= t;
-            q.push(t);
+            pq.push(t);
             ++ans;
         }
         return ans;
@@ -156,17 +156,17 @@ public:
 ```go
 func halveArray(nums []int) (ans int) {
 	var s float64
-	q := hp{}
+	pq := &hp{}
 	for _, x := range nums {
 		s += float64(x)
-		heap.Push(&q, float64(x))
+		heap.Push(pq, float64(x))
 	}
 	s /= 2
 	for s > 0 {
-		x := heap.Pop(&q).(float64)
+		t := heap.Pop(pq).(float64) / 2
+		s -= t
 		ans++
-		s -= x / 2
-		heap.Push(&q, x/2)
+		heap.Push(pq, t)
 	}
 	return
 }
@@ -188,17 +188,16 @@ func (h *hp) Pop() any {
 ```ts
 function halveArray(nums: number[]): number {
     let s: number = nums.reduce((a, b) => a + b) / 2;
-    const h = new MaxPriorityQueue();
-    for (const v of nums) {
-        h.enqueue(v, v);
+    const pq = new MaxPriorityQueue();
+    for (const x of nums) {
+        pq.enqueue(x, x);
     }
-    let ans: number = 0;
+    let ans = 0;
     while (s > 0) {
-        let { element: t } = h.dequeue();
-        t /= 2;
+        const t = pq.dequeue().element / 2;
         s -= t;
-        h.enqueue(t, t);
-        ans += 1;
+        ++ans;
+        pq.enqueue(t, t);
     }
     return ans;
 }
@@ -208,40 +207,4 @@ function halveArray(nums: number[]): number {
 
 <!-- solution:end -->
 
-<!-- solution:start -->
-
-### 方法二
-
-<!-- tabs:start -->
-
-#### Go
-
-```go
-func halveArray(nums []int) (ans int) {
-	half := 0
-	for i := range nums {
-		nums[i] <<= 20
-		half += nums[i]
-	}
-	h := hp{nums}
-	heap.Init(&h)
-	for half >>= 1; half > 0; ans++ {
-		half -= h.IntSlice[0] >> 1
-		h.IntSlice[0] >>= 1
-		heap.Fix(&h, 0)
-	}
-	return
-}
-
-type hp struct{ sort.IntSlice }
-
-func (h hp) Less(i, j int) bool { return h.IntSlice[i] > h.IntSlice[j] }
-func (hp) Push(any)             {}
-func (hp) Pop() (_ any)         { return }
-```
-
-<!-- tabs:end -->
-
-<!-- solution:end -->
-
 <!-- problem:end -->

solution/2200-2299/2208.Minimum Operations to Halve Array Sum/README_EN.md

@@ -35,7 +35,7 @@ The following is one of the ways to reduce the sum by at least half:
 Pick the number 19 and reduce it to 9.5.
 Pick the number 9.5 and reduce it to 4.75.
 Pick the number 8 and reduce it to 4.
-The final array is [5, 4.75, 4, 1] with a total sum of 5 + 4.75 + 4 + 1 = 14.75. 
+The final array is [5, 4.75, 4, 1] with a total sum of 5 + 4.75 + 4 + 1 = 14.75.
 The sum of nums has been reduced by 33 - 14.75 = 18.25, which is at least half of the initial sum, 18.25 >= 33/2 = 16.5.
 Overall, 3 operations were used so we return 3.
 It can be shown that we cannot reduce the sum by at least half in less than 3 operations.
@@ -51,7 +51,7 @@ The following is one of the ways to reduce the sum by at least half:
 Pick the number 20 and reduce it to 10.
 Pick the number 10 and reduce it to 5.
 Pick the number 3 and reduce it to 1.5.
-The final array is [1.5, 8, 5] with a total sum of 1.5 + 8 + 5 = 14.5. 
+The final array is [1.5, 8, 5] with a total sum of 1.5 + 8 + 5 = 14.5.
 The sum of nums has been reduced by 31 - 14.5 = 16.5, which is at least half of the initial sum, 16.5 >= 31/2 = 15.5.
 Overall, 3 operations were used so we return 3.
 It can be shown that we cannot reduce the sum by at least half in less than 3 operations.
@@ -87,14 +87,14 @@ The time complexity is $O(n \times \log n)$, and the space complexity is $O(n)$.
 class Solution:
     def halveArray(self, nums: List[int]) -> int:
         s = sum(nums) / 2
-        h = []
-        for v in nums:
-            heappush(h, -v)
+        pq = []
+        for x in nums:
+            heappush(pq, -x)
         ans = 0
         while s > 0:
-            t = -heappop(h) / 2
+            t = -heappop(pq) / 2
             s -= t
-            heappush(h, -t)
+            heappush(pq, -t)
             ans += 1
         return ans
 ```
@@ -104,18 +104,18 @@ class Solution:
 ```java
 class Solution {
     public int halveArray(int[] nums) {
+        PriorityQueue<Double> pq = new PriorityQueue<>(Collections.reverseOrder());
         double s = 0;
-        PriorityQueue<Double> q = new PriorityQueue<>(Collections.reverseOrder());
-        for (int v : nums) {
-            q.offer(v * 1.0);
-            s += v;
+        for (int x : nums) {
+            s += x;
+            pq.offer((double) x);
         }
         s /= 2.0;
         int ans = 0;
         while (s > 0) {
-            double t = q.poll();
-            s -= t / 2.0;
-            q.offer(t / 2.0);
+            double t = pq.poll() / 2.0;
+            s -= t;
+            pq.offer(t);
             ++ans;
         }
         return ans;
@@ -129,19 +129,19 @@ class Solution {
 class Solution {
 public:
     int halveArray(vector<int>& nums) {
-        priority_queue<double> q;
+        priority_queue<double> pq;
         double s = 0;
-        for (int& v : nums) {
-            s += v;
-            q.push(v);
+        for (int x : nums) {
+            s += x;
+            pq.push((double) x);
         }
         s /= 2.0;
         int ans = 0;
         while (s > 0) {
-            double t = q.top() / 2;
-            q.pop();
+            double t = pq.top() / 2.0;
+            pq.pop();
             s -= t;
-            q.push(t);
+            pq.push(t);
             ++ans;
         }
         return ans;
@@ -154,17 +154,17 @@ public:
 ```go
 func halveArray(nums []int) (ans int) {
 	var s float64
-	q := hp{}
+	pq := &hp{}
 	for _, x := range nums {
 		s += float64(x)
-		heap.Push(&q, float64(x))
+		heap.Push(pq, float64(x))
 	}
 	s /= 2
 	for s > 0 {
-		x := heap.Pop(&q).(float64)
+		t := heap.Pop(pq).(float64) / 2
+		s -= t
 		ans++
-		s -= x / 2
-		heap.Push(&q, x/2)
+		heap.Push(pq, t)
 	}
 	return
 }
@@ -186,17 +186,16 @@ func (h *hp) Pop() any {
 ```ts
 function halveArray(nums: number[]): number {
     let s: number = nums.reduce((a, b) => a + b) / 2;
-    const h = new MaxPriorityQueue();
-    for (const v of nums) {
-        h.enqueue(v, v);
+    const pq = new MaxPriorityQueue();
+    for (const x of nums) {
+        pq.enqueue(x, x);
     }
-    let ans: number = 0;
+    let ans = 0;
     while (s > 0) {
-        let { element: t } = h.dequeue();
-        t /= 2;
+        const t = pq.dequeue().element / 2;
         s -= t;
-        h.enqueue(t, t);
-        ans += 1;
+        ++ans;
+        pq.enqueue(t, t);
     }
     return ans;
 }
@@ -206,40 +205,4 @@ function halveArray(nums: number[]): number {
 
 <!-- solution:end -->
 
-<!-- solution:start -->
-
-### Solution 2
-
-<!-- tabs:start -->
-
-#### Go
-
-```go
-func halveArray(nums []int) (ans int) {
-	half := 0
-	for i := range nums {
-		nums[i] <<= 20
-		half += nums[i]
-	}
-	h := hp{nums}
-	heap.Init(&h)
-	for half >>= 1; half > 0; ans++ {
-		half -= h.IntSlice[0] >> 1
-		h.IntSlice[0] >>= 1
-		heap.Fix(&h, 0)
-	}
-	return
-}
-
-type hp struct{ sort.IntSlice }
-
-func (h hp) Less(i, j int) bool { return h.IntSlice[i] > h.IntSlice[j] }
-func (hp) Push(any)             {}
-func (hp) Pop() (_ any)         { return }
-```
-
-<!-- tabs:end -->
-
-<!-- solution:end -->
-
 <!-- problem:end -->

solution/2200-2299/2208.Minimum Operations to Halve Array Sum/Solution.cpp

@@ -1,21 +1,21 @@
 class Solution {
 public:
     int halveArray(vector<int>& nums) {
-        priority_queue<double> q;
+        priority_queue<double> pq;
         double s = 0;
-        for (int& v : nums) {
-            s += v;
-            q.push(v);
+        for (int x : nums) {
+            s += x;
+            pq.push((double) x);
         }
         s /= 2.0;
         int ans = 0;
         while (s > 0) {
-            double t = q.top() / 2;
-            q.pop();
+            double t = pq.top() / 2.0;
+            pq.pop();
             s -= t;
-            q.push(t);
+            pq.push(t);
             ++ans;
         }
         return ans;
     }
-};
+};