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Commit ff04023

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feat: add solutions to lc problem: No.2208 (doocs#3537)
No.2208.Minimum Operations to Halve Array Sum
1 parent ec27a55 commit ff04023

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8 files changed

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-194
lines changed

8 files changed

+98
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‎solution/2200-2299/2208.Minimum Operations to Halve Array Sum/README.md‎

Lines changed: 31 additions & 68 deletions
Original file line numberDiff line numberDiff line change
@@ -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
8989
class Solution:
9090
def halveArray(self, nums: List[int]) -> int:
9191
s = sum(nums) / 2
92-
h = []
93-
for v in nums:
94-
heappush(h, -v)
92+
pq = []
93+
for x in nums:
94+
heappush(pq, -x)
9595
ans = 0
9696
while s > 0:
97-
t = -heappop(h) / 2
97+
t = -heappop(pq) / 2
9898
s -= t
99-
heappush(h, -t)
99+
heappush(pq, -t)
100100
ans += 1
101101
return ans
102102
```
@@ -106,18 +106,18 @@ class Solution:
106106
```java
107107
class Solution {
108108
public int halveArray(int[] nums) {
109+
PriorityQueue<Double> pq = new PriorityQueue<>(Collections.reverseOrder());
109110
double s = 0;
110-
PriorityQueue<Double> q = new PriorityQueue<>(Collections.reverseOrder());
111-
for (int v : nums) {
112-
q.offer(v * 1.0);
113-
s += v;
111+
for (int x : nums) {
112+
s += x;
113+
pq.offer((double) x);
114114
}
115115
s /= 2.0;
116116
int ans = 0;
117117
while (s > 0) {
118-
double t = q.poll();
119-
s -= t/2.0;
120-
q.offer(t/2.0);
118+
double t = pq.poll()/2.0;
119+
s -= t;
120+
pq.offer(t);
121121
++ans;
122122
}
123123
return ans;
@@ -131,19 +131,19 @@ class Solution {
131131
class Solution {
132132
public:
133133
int halveArray(vector<int>& nums) {
134-
priority_queue<double> q;
134+
priority_queue<double> pq;
135135
double s = 0;
136-
for (int& v : nums) {
137-
s += v;
138-
q.push(v);
136+
for (int x : nums) {
137+
s += x;
138+
pq.push((double) x);
139139
}
140140
s /= 2.0;
141141
int ans = 0;
142142
while (s > 0) {
143-
double t = q.top() / 2;
144-
q.pop();
143+
double t = pq.top() / 2.0;
144+
pq.pop();
145145
s -= t;
146-
q.push(t);
146+
pq.push(t);
147147
++ans;
148148
}
149149
return ans;
@@ -156,17 +156,17 @@ public:
156156
```go
157157
func halveArray(nums []int) (ans int) {
158158
var s float64
159-
q := hp{}
159+
pq := &hp{}
160160
for _, x := range nums {
161161
s += float64(x)
162-
heap.Push(&q, float64(x))
162+
heap.Push(pq, float64(x))
163163
}
164164
s /= 2
165165
for s > 0 {
166-
x := heap.Pop(&q).(float64)
166+
t := heap.Pop(pq).(float64) / 2
167+
s -= t
167168
ans++
168-
s -= x / 2
169-
heap.Push(&q, x/2)
169+
heap.Push(pq, t)
170170
}
171171
return
172172
}
@@ -188,17 +188,16 @@ func (h *hp) Pop() any {
188188
```ts
189189
function halveArray(nums: number[]): number {
190190
let s: number = nums.reduce((a, b) => a + b) / 2;
191-
const h = new MaxPriorityQueue();
192-
for (const v of nums) {
193-
h.enqueue(v, v);
191+
const pq = new MaxPriorityQueue();
192+
for (const x of nums) {
193+
pq.enqueue(x, x);
194194
}
195-
let ans:number = 0;
195+
let ans = 0;
196196
while (s > 0) {
197-
let { element: t } = h.dequeue();
198-
t /= 2;
197+
const t = pq.dequeue().element / 2;
199198
s -= t;
200-
h.enqueue(t, t);
201-
ans+=1;
199+
++ans;
200+
pq.enqueue(t, t);
202201
}
203202
return ans;
204203
}
@@ -208,40 +207,4 @@ function halveArray(nums: number[]): number {
208207

209208
<!-- solution:end -->
210209

211-
<!-- solution:start -->
212-
213-
### 方法二
214-
215-
<!-- tabs:start -->
216-
217-
#### Go
218-
219-
```go
220-
func halveArray(nums []int) (ans int) {
221-
half := 0
222-
for i := range nums {
223-
nums[i] <<= 20
224-
half += nums[i]
225-
}
226-
h := hp{nums}
227-
heap.Init(&h)
228-
for half >>= 1; half > 0; ans++ {
229-
half -= h.IntSlice[0] >> 1
230-
h.IntSlice[0] >>= 1
231-
heap.Fix(&h, 0)
232-
}
233-
return
234-
}
235-
236-
type hp struct{ sort.IntSlice }
237-
238-
func (h hp) Less(i, j int) bool { return h.IntSlice[i] > h.IntSlice[j] }
239-
func (hp) Push(any) {}
240-
func (hp) Pop() (_ any) { return }
241-
```
242-
243-
<!-- tabs:end -->
244-
245-
<!-- solution:end -->
246-
247210
<!-- problem:end -->

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

Lines changed: 33 additions & 70 deletions
Original file line numberDiff line numberDiff line change
@@ -35,7 +35,7 @@ The following is one of the ways to reduce the sum by at least half:
3535
Pick the number 19 and reduce it to 9.5.
3636
Pick the number 9.5 and reduce it to 4.75.
3737
Pick the number 8 and reduce it to 4.
38-
The final array is [5, 4.75, 4, 1] with a total sum of 5 + 4.75 + 4 + 1 = 14.75.
38+
The final array is [5, 4.75, 4, 1] with a total sum of 5 + 4.75 + 4 + 1 = 14.75.
3939
The sum of nums has been reduced by 33 - 14.75 = 18.25, which is at least half of the initial sum, 18.25 &gt;= 33/2 = 16.5.
4040
Overall, 3 operations were used so we return 3.
4141
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:
5151
Pick the number 20 and reduce it to 10.
5252
Pick the number 10 and reduce it to 5.
5353
Pick the number 3 and reduce it to 1.5.
54-
The final array is [1.5, 8, 5] with a total sum of 1.5 + 8 + 5 = 14.5.
54+
The final array is [1.5, 8, 5] with a total sum of 1.5 + 8 + 5 = 14.5.
5555
The sum of nums has been reduced by 31 - 14.5 = 16.5, which is at least half of the initial sum, 16.5 &gt;= 31/2 = 15.5.
5656
Overall, 3 operations were used so we return 3.
5757
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),ドル and the space complexity is $O(n)$.
8787
class Solution:
8888
def halveArray(self, nums: List[int]) -> int:
8989
s = sum(nums) / 2
90-
h = []
91-
for v in nums:
92-
heappush(h, -v)
90+
pq = []
91+
for x in nums:
92+
heappush(pq, -x)
9393
ans = 0
9494
while s > 0:
95-
t = -heappop(h) / 2
95+
t = -heappop(pq) / 2
9696
s -= t
97-
heappush(h, -t)
97+
heappush(pq, -t)
9898
ans += 1
9999
return ans
100100
```
@@ -104,18 +104,18 @@ class Solution:
104104
```java
105105
class Solution {
106106
public int halveArray(int[] nums) {
107+
PriorityQueue<Double> pq = new PriorityQueue<>(Collections.reverseOrder());
107108
double s = 0;
108-
PriorityQueue<Double> q = new PriorityQueue<>(Collections.reverseOrder());
109-
for (int v : nums) {
110-
q.offer(v * 1.0);
111-
s += v;
109+
for (int x : nums) {
110+
s += x;
111+
pq.offer((double) x);
112112
}
113113
s /= 2.0;
114114
int ans = 0;
115115
while (s > 0) {
116-
double t = q.poll();
117-
s -= t/2.0;
118-
q.offer(t/2.0);
116+
double t = pq.poll()/2.0;
117+
s -= t;
118+
pq.offer(t);
119119
++ans;
120120
}
121121
return ans;
@@ -129,19 +129,19 @@ class Solution {
129129
class Solution {
130130
public:
131131
int halveArray(vector<int>& nums) {
132-
priority_queue<double> q;
132+
priority_queue<double> pq;
133133
double s = 0;
134-
for (int& v : nums) {
135-
s += v;
136-
q.push(v);
134+
for (int x : nums) {
135+
s += x;
136+
pq.push((double) x);
137137
}
138138
s /= 2.0;
139139
int ans = 0;
140140
while (s > 0) {
141-
double t = q.top() / 2;
142-
q.pop();
141+
double t = pq.top() / 2.0;
142+
pq.pop();
143143
s -= t;
144-
q.push(t);
144+
pq.push(t);
145145
++ans;
146146
}
147147
return ans;
@@ -154,17 +154,17 @@ public:
154154
```go
155155
func halveArray(nums []int) (ans int) {
156156
var s float64
157-
q := hp{}
157+
pq := &hp{}
158158
for _, x := range nums {
159159
s += float64(x)
160-
heap.Push(&q, float64(x))
160+
heap.Push(pq, float64(x))
161161
}
162162
s /= 2
163163
for s > 0 {
164-
x := heap.Pop(&q).(float64)
164+
t := heap.Pop(pq).(float64) / 2
165+
s -= t
165166
ans++
166-
s -= x / 2
167-
heap.Push(&q, x/2)
167+
heap.Push(pq, t)
168168
}
169169
return
170170
}
@@ -186,17 +186,16 @@ func (h *hp) Pop() any {
186186
```ts
187187
function halveArray(nums: number[]): number {
188188
let s: number = nums.reduce((a, b) => a + b) / 2;
189-
const h = new MaxPriorityQueue();
190-
for (const v of nums) {
191-
h.enqueue(v, v);
189+
const pq = new MaxPriorityQueue();
190+
for (const x of nums) {
191+
pq.enqueue(x, x);
192192
}
193-
let ans:number = 0;
193+
let ans = 0;
194194
while (s > 0) {
195-
let { element: t } = h.dequeue();
196-
t /= 2;
195+
const t = pq.dequeue().element / 2;
197196
s -= t;
198-
h.enqueue(t, t);
199-
ans+=1;
197+
++ans;
198+
pq.enqueue(t, t);
200199
}
201200
return ans;
202201
}
@@ -206,40 +205,4 @@ function halveArray(nums: number[]): number {
206205

207206
<!-- solution:end -->
208207

209-
<!-- solution:start -->
210-
211-
### Solution 2
212-
213-
<!-- tabs:start -->
214-
215-
#### Go
216-
217-
```go
218-
func halveArray(nums []int) (ans int) {
219-
half := 0
220-
for i := range nums {
221-
nums[i] <<= 20
222-
half += nums[i]
223-
}
224-
h := hp{nums}
225-
heap.Init(&h)
226-
for half >>= 1; half > 0; ans++ {
227-
half -= h.IntSlice[0] >> 1
228-
h.IntSlice[0] >>= 1
229-
heap.Fix(&h, 0)
230-
}
231-
return
232-
}
233-
234-
type hp struct{ sort.IntSlice }
235-
236-
func (h hp) Less(i, j int) bool { return h.IntSlice[i] > h.IntSlice[j] }
237-
func (hp) Push(any) {}
238-
func (hp) Pop() (_ any) { return }
239-
```
240-
241-
<!-- tabs:end -->
242-
243-
<!-- solution:end -->
244-
245208
<!-- problem:end -->
Lines changed: 8 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1,21 +1,21 @@
11
class Solution {
22
public:
33
int halveArray(vector<int>& nums) {
4-
priority_queue<double> q;
4+
priority_queue<double> pq;
55
double s = 0;
6-
for (int& v : nums) {
7-
s += v;
8-
q.push(v);
6+
for (int x : nums) {
7+
s += x;
8+
pq.push((double) x);
99
}
1010
s /= 2.0;
1111
int ans = 0;
1212
while (s > 0) {
13-
double t = q.top() / 2;
14-
q.pop();
13+
double t = pq.top() / 2.0;
14+
pq.pop();
1515
s -= t;
16-
q.push(t);
16+
pq.push(t);
1717
++ans;
1818
}
1919
return ans;
2020
}
21-
};
21+
};

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