@@ -113,9 +113,13 @@ public:
113113 f[ 0] = 0;
114114 deque<int > q = {0};
115115 for (int i = 0; i < n; ++i) {
116- if (i - q.front() > k) q.pop_front();
116+ if (i - q.front() > k) {
117+ q.pop_front();
118+ }
117119 f[ i] = nums[ i] + f[ q.front()] ;
118- while (!q.empty() && f[ q.back()] <= f[ i] ) q.pop_back();
120+ while (!q.empty() && f[ i] >= f[ q.back()] ) {
121+ q.pop_back();
122+ }
119123 q.push_back(i);
120124 }
121125 return f[ n - 1] ;
@@ -127,19 +131,193 @@ public:
127131func maxResult(nums []int, k int) int {
128132 n := len(nums)
129133 f := make([]int, n)
130- q := []int{0}
131- for i, v := range nums {
132- if i-q[0] > k {
133- q = q[1:]
134+ q := Deque{}
135+ q.PushBack(0)
136+ for i := 0; i < n; i++ {
137+ if i-q.Front() > k {
138+ q.PopFront()
134139 }
135- f[i] = v + f[q[0] ]
136- for len(q) > 0 && f[q[len(q)-1]] < = f[i ] {
137- q = q[:len(q)-1]
140+ f[i] = nums[i] + f[q.Front() ]
141+ for !q.Empty() && f[i] > = f[q.Back() ] {
142+ q.PopBack()
138143 }
139- q = append(q, i)
144+ q.PushBack( i)
140145 }
141146 return f[n-1]
142147}
148+
149+ type Deque struct{ l, r []int }
150+
151+ func (q Deque) Empty() bool {
152+ return len(q.l) == 0 && len(q.r) == 0
153+ }
154+
155+ func (q Deque) Size() int {
156+ return len(q.l) + len(q.r)
157+ }
158+
159+ func (q *Deque) PushFront(v int) {
160+ q.l = append(q.l, v)
161+ }
162+
163+ func (q *Deque) PushBack(v int) {
164+ q.r = append(q.r, v)
165+ }
166+
167+ func (q *Deque) PopFront() (v int) {
168+ if len(q.l) > 0 {
169+ q.l, v = q.l[:len(q.l)-1], q.l[len(q.l)-1]
170+ } else {
171+ v, q.r = q.r[0], q.r[1:]
172+ }
173+ return
174+ }
175+
176+ func (q *Deque) PopBack() (v int) {
177+ if len(q.r) > 0 {
178+ q.r, v = q.r[:len(q.r)-1], q.r[len(q.r)-1]
179+ } else {
180+ v, q.l = q.l[0], q.l[1:]
181+ }
182+ return
183+ }
184+
185+ func (q Deque) Front() int {
186+ if len(q.l) > 0 {
187+ return q.l[len(q.l)-1]
188+ }
189+ return q.r[0]
190+ }
191+
192+ func (q Deque) Back() int {
193+ if len(q.r) > 0 {
194+ return q.r[len(q.r)-1]
195+ }
196+ return q.l[0]
197+ }
198+
199+ func (q Deque) Get(i int) int {
200+ if i < len(q.l) {
201+ return q.l[len(q.l)-1-i]
202+ }
203+ return q.r[i-len(q.l)]
204+ }
205+ ```
206+ 207+ ``` ts
208+ function maxResult(nums : number [], k : number ): number {
209+ const = nums .length ;
210+ const : number [] = Array (n ).fill (0 );
211+ const = new Deque <number >();
212+ q .pushBack (0 );
213+ for (let i = 0 ; i < n ; ++ i ) {
214+ if (i - q .frontValue ()! > k ) {
215+ q .popFront ();
216+ }
217+ f [i ] = nums [i ] + f [q .frontValue ()! ];
218+ while (! q .isEmpty () && f [i ] >= f [q .backValue ()! ]) {
219+ q .popBack ();
220+ }
221+ q .pushBack (i );
222+ }
223+ return f [n - 1 ];
224+ }
225+ 226+ class Node <T > {
227+ value: T ;
228+ next: Node <T > | null ;
229+ prev: Node <T > | null ;
230+ 231+ constructor (value : T ) {
232+ this .value = value ;
233+ this .next = null ;
234+ this .prev = null ;
235+ }
236+ }
237+ 238+ class Deque <T > {
239+ private front: Node <T > | null ;
240+ private back: Node <T > | null ;
241+ private size: number ;
242+ 243+ constructor () {
244+ this .front = null ;
245+ this .back = null ;
246+ this .size = 0 ;
247+ }
248+ 249+ pushFront(val : T ): void {
250+ const = new Node (val );
251+ if (this .isEmpty ()) {
252+ this .front = newNode ;
253+ this .back = newNode ;
254+ } else {
255+ newNode .next = this .front ;
256+ this .front ! .prev = newNode ;
257+ this .front = newNode ;
258+ }
259+ this .size ++ ;
260+ }
261+ 262+ pushBack(val : T ): void {
263+ const = new Node (val );
264+ if (this .isEmpty ()) {
265+ this .front = newNode ;
266+ this .back = newNode ;
267+ } else {
268+ newNode .prev = this .back ;
269+ this .back ! .next = newNode ;
270+ this .back = newNode ;
271+ }
272+ this .size ++ ;
273+ }
274+ 275+ popFront(): T | undefined {
276+ if (this .isEmpty ()) {
277+ return undefined ;
278+ }
279+ const = this .front ! .value ;
280+ this .front = this .front ! .next ;
281+ if (this .front !== null ) {
282+ this .front .prev = null ;
283+ } else {
284+ this .back = null ;
285+ }
286+ this .size -- ;
287+ return value ;
288+ }
289+ 290+ popBack(): T | undefined {
291+ if (this .isEmpty ()) {
292+ return undefined ;
293+ }
294+ const = this .back ! .value ;
295+ this .back = this .back ! .prev ;
296+ if (this .back !== null ) {
297+ this .back .next = null ;
298+ } else {
299+ this .front = null ;
300+ }
301+ this .size -- ;
302+ return value ;
303+ }
304+ 305+ frontValue(): T | undefined {
306+ return this .front ?.value ;
307+ }
308+ 309+ backValue(): T | undefined {
310+ return this .back ?.value ;
311+ }
312+ 313+ getSize(): number {
314+ return this .size ;
315+ }
316+ 317+ isEmpty(): boolean {
318+ return this .size === 0 ;
319+ }
320+ }
143321```
144322
145323<!-- tabs: end -->
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