Java Code Examples for java.util.Deque#peekFirst()
The following examples show how to use
java.util.Deque#peekFirst() .
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Example 1
Source File: Solution.java From daily-coding-problems with Apache License 2.0 | 6 votes |
int[] getMaximumInSubArray(int[] array, int window) { List<Integer> result = new ArrayList<>(); if (array == null || array.length == 0) { return new int[0]; } if (window > array.length) { throw new IllegalArgumentException("window should be less than the array length"); } Deque<Integer> deque = new ArrayDeque<>(); for (int index = 0; index < array.length; index++) { if (!deque.isEmpty() && deque.peekFirst() == index - window) { deque.removeFirst(); } while (!deque.isEmpty() && array[index] > array[deque.peekLast()]) { deque.removeLast(); } deque.addLast(index); if (index >= window - 1) { result.add(array[deque.peekFirst()]); } } return result.stream().mapToInt(x -> x).toArray(); }
Example 2
Source File: Helper.java From FrameworkBenchmarks with BSD 3-Clause "New" or "Revised" License | 6 votes |
/** * Returns the value of the "queries" request parameter, which is an integer * bound between 1 and 500 with a default value of 1. * * @param exchange the current HTTP exchange * @return the value of the "queries" request parameter */ public static int getQueries(HttpServerExchange exchange) { Deque<String> values = exchange.getQueryParameters().get("queries"); if (values == null) { return 1; } String textValue = values.peekFirst(); if (textValue == null) { return 1; } try { int parsedValue = Integer.parseInt(textValue); return Math.min(500, Math.max(1, parsedValue)); } catch (NumberFormatException e) { return 1; } }
Example 3
Source File: LinkedDequeTest.java From concurrentlinkedhashmap with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void removeLastOccurrence_whenFound(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.removeLastOccurrence(first), is(true)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 4
Source File: TreeTraversalInSpiralOrder.java From interview with Apache License 2.0 | 5 votes |
/** * One deque with delimiter to print tree in spiral order */ public void spiralWithOneDequeDelimiter(Node root) { if(root == null){ return; } Deque<Node> q = new LinkedList<>(); q.offer(null); q.offerFirst(root); //if only delimiter(in this case null) is left in queue then break while(q.size() > 1){ root = q.peekFirst(); while(root != null){ root = q.pollFirst(); System.out.print(root.data + " "); if(root.left != null){ q.offerLast(root.left); } if(root.right != null){ q.offerLast(root.right); } root = q.peekFirst(); } root = q.peekLast(); while(root != null){ System.out.print(root.data + " "); root = q.pollLast(); if(root.right != null){ q.offerFirst(root.right); } if(root.left != null){ q.offerFirst(root.left); } root = q.peekLast(); } } }
Example 5
Source File: LinkedDequeTest.java From multiway-pool with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void removeFirstOccurrence_whenFound(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.removeFirstOccurrence(first), is(true)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 6
Source File: LinkedDequeTest.java From concurrentlinkedhashmap with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void removeElement_whenFound(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.remove(first), is(true)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 7
Source File: ASTReference.java From velocity-engine with Apache License 2.0 | 5 votes |
/** * This method helps to implement the "render literal if null" functionality. * * VelocimacroProxy saves references to macro arguments (AST nodes) so that if we have a macro * #foobar($a $b) then there is key "$a.literal" which points to the literal presentation of the * argument provided to variable $a. If the value of $a is null, we render the string that was * provided as the argument. * * @param context * @return */ private String getNullString(InternalContextAdapter context) { String ret = nullString; if (lookupAlternateLiteral) { Deque<String> alternateLiteralsStack = (Deque<String>)context.get(alternateNullStringKey); if (alternateLiteralsStack != null && alternateLiteralsStack.size() > 0) { ret = alternateLiteralsStack.peekFirst(); } } return ret; }
Example 8
Source File: Test65.java From algorithm-primer with MIT License | 5 votes |
public ArrayList<Integer> maxInWindows(int[] num, int size) { ArrayList<Integer> result = new ArrayList<>(); if (num == null || num.length == 0 || size < 1) return result; Deque<Integer> deque = new LinkedList<>(); for (int i = 0; i < num.length; i ++){ // 保证添加新的元素之前,窗口中首尾元素下标之差最大是size if (i > 0 && !deque.isEmpty()){ int firstIdx = deque.peekFirst(); int diff = i - firstIdx; if (diff == size) deque.pollFirst(); } /* if (!deque.isEmpty() && num[i] > deque.peekFirst()){ deque.clear(); }else{ while(!deque.isEmpty() && num[i] >= deque.peekLast()) deque.pollLast(); } */ // 同一个窗口中的元素如果小于新元素,则被删除 // 由于前面的元素总是大于后面的元素,所以从后面开始删除 while(!deque.isEmpty() && num[i] >= num[deque.peekLast()]) deque.pollLast(); // 新元素总是会被添加到双端队列的末尾 deque.offerLast(i); // 双端队列的队头存放的是一个窗口的最大值 if (i >= size-1) result.add(num[deque.peekFirst()]); } return result; }
Example 9
Source File: LinkedDequeTest.java From multiway-pool with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void removeElement_whenFound(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.remove(first), is(true)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 10
Source File: LinkedDequeTest.java From concurrentlinkedhashmap with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void pollFirst_whenPopulated(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.pollFirst(), is(first)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 11
Source File: RemoveExtraBrackets.java From interview with Apache License 2.0 | 5 votes |
public int remove(char input[]){ if(input == null){ return 0; } Deque<Integer> dq = new LinkedList<Integer>(); for(int i=0; i < input.length; i++){ //skip non bracket characters if(input[i] != '(' && input[i] != ')'){ continue; } //add opening brackets if(input[i] == '('){ dq.addFirst(i); } else if(input[i] == ')'){ //if top is opening bracket just remove from stack else add closing bracket if(!dq.isEmpty() && input[dq.peekFirst()] == '('){ dq.pollFirst(); }else{ dq.addFirst(i); } } } int index = 0; //iterate through list again and don't add leftover //characters from stack in final result for(int i=0; i < input.length; i++){ if(!dq.isEmpty() && i == dq.peekLast()) { dq.pollLast(); }else { input[index++] = input[i]; } } return index; }
Example 12
Source File: MaximumOfSubarrayOfSizeK.java From interview with Apache License 2.0 | 5 votes |
public int[] maxSubArray(int input[], int k) { Deque<Integer> queue = new LinkedList<Integer>(); int max[] = new int[input.length - k + 1]; int maxVal = Integer.MIN_VALUE; //first find max of first k values and make it 0th element of max array for (int i = 0; i < k; i++) { if(maxVal < input[i]){ maxVal = input[i]; } if (queue.isEmpty()) { queue.offerLast(i); } else { while (!queue.isEmpty() && input[queue.peekLast()] <= input[i]) { queue.pollLast(); } queue.offerLast(i); } } max[0] = maxVal; int index=1; //continue from k till end of the input array for (int i = k; i < input.length; i++) { //if index of peek is k distance from i then its no value to us. //throw it away if (i - k + 1 > queue.peekFirst()) { queue.pollFirst(); } while (!queue.isEmpty() && input[queue.peekLast()] <= input[i]) { queue.pollLast(); } queue.offerLast(i); //Only reason first element survived was because it was biggest element. //make it the max value for this k max[index] = input[queue.peekFirst()]; index++; } return max; }
Example 13
Source File: LinkedDequeTest.java From multiway-pool with Apache License 2.0 | 5 votes |
@Test(dataProvider = "warmedDeque") public void removeFirst_whenPopulated(Deque<SimpleLinkedValue> deque) { SimpleLinkedValue first = deque.peekFirst(); assertThat(deque.removeFirst(), is(first)); assertThat(deque, hasSize((int) capacity() - 1)); assertThat(deque.contains(first), is(false)); }
Example 14
Source File: MCRFileSystemUtils.java From mycore with GNU General Public License v3.0 | 4 votes |
static MCRFile getMCRFile(MCRDirectory baseDir, MCRPath relativePath, boolean create, boolean createNew) throws IOException { MCRPath ifsPath = relativePath; if (relativePath.isAbsolute()) { if (baseDir.getOwnerID().equals(relativePath.getOwner())) { ifsPath = baseDir.toPath().relativize(relativePath); } else { throw new IOException(relativePath + " is absolute does not fit to " + baseDir.toPath()); } } Deque<MCRFilesystemNode> created = new LinkedList<>(); MCRFile file; try { file = (MCRFile) baseDir.getChildByPath(ifsPath.toString()); if (file != null && createNew) { throw new FileAlreadyExistsException(baseDir.toPath().resolve(ifsPath).toString()); } if (file == null & (create || createNew)) { Path normalized = ifsPath.normalize(); MCRDirectory parent = baseDir; int nameCount = normalized.getNameCount(); int directoryCount = nameCount - 1; int i = 0; while (i < directoryCount) { String curName = normalized.getName(i).toString(); MCRDirectory curDir = (MCRDirectory) parent.getChild(curName); if (curDir == null) { curDir = new MCRDirectory(curName, parent); created.addFirst(curDir); } i++; parent = curDir; } String fileName = normalized.getFileName().toString(); file = new MCRFile(fileName, parent); file.setContentFrom(new ByteArrayInputStream(new byte[0]), false);//false -> no event handler created.addFirst(file); } } catch (Exception e) { if (create || createNew) { LOGGER.error("Exception while getting MCRFile {}. Removing created filesystem nodes.", ifsPath); while (created.peekFirst() != null) { MCRFilesystemNode node = created.pollFirst(); try { node.delete(); } catch (Exception de) { LOGGER.fatal("Error while deleting file system node: {}", node.getName(), de); } } } throw e; } return file; }
Example 15
Source File: PrintTwoBSTInSortedForm.java From interview with Apache License 2.0 | 4 votes |
public void print(Node root1, Node root2){ Deque<Node> s1 = new LinkedList<Node>(); Deque<Node> s2 = new LinkedList<Node>(); while(true){ if(root1 != null){ s1.addFirst(root1); root1 = root1.left; continue; } if(root2 != null){ s2.addFirst(root2); root2 = root2.left; continue; } if(!s1.isEmpty()){ root1 = s1.peekFirst(); } if(!s2.isEmpty()){ root2 = s2.peekFirst(); } if(root1 != null && root2 != null){ if(root1.data <= root2.data){ System.out.println(root1.data); root1 = s1.pollFirst(); root1 = root1.right; root2 = null; }else{ System.out.println(root2.data); root2 = s2.pollFirst(); root2 = root2.right; root1 = null; } } else if(root1 != null){ System.out.println(root1.data); root1 = s1.pollFirst(); root1 = root1.right; }else if(root2 != null){ System.out.println(root2.data); root2 = s2.pollFirst(); root2 = root2.right; } if(root1 == null && root2 == null && s1.isEmpty() && s2.isEmpty()){ break; } } }
Example 16
Source File: FormData.java From lams with GNU General Public License v2.0 | 4 votes |
public FormValue getFirst(String name) { final Deque<FormValue> deque = values.get(name); return deque == null ? null : deque.peekFirst(); }
Example 17
Source File: JavaInputAstVisitor.java From google-java-format with Apache License 2.0 | 4 votes |
/** * Output a chain of dereferences where some prefix should be treated as a single syntactic unit, * either because it looks like a type name or because there is only a single method invocation in * the chain. * * @param items in the chain * @param needDot whether a leading dot is needed * @param prefixes the terminal indices of 'prefixes' of the expression that should be treated as * a syntactic unit */ private void visitDotWithPrefix( List<ExpressionTree> items, boolean needDot, Collection<Integer> prefixes, FillMode prefixFillMode) { // Are there method invocations or field accesses after the prefix? boolean trailingDereferences = !prefixes.isEmpty() && getLast(prefixes) < items.size() - 1; builder.open(plusFour); for (int times = 0; times < prefixes.size(); times++) { builder.open(ZERO); } Deque<Integer> unconsumedPrefixes = new ArrayDeque<>(ImmutableSortedSet.copyOf(prefixes)); BreakTag nameTag = genSym(); for (int i = 0; i < items.size(); i++) { ExpressionTree e = items.get(i); if (needDot) { FillMode fillMode; if (!unconsumedPrefixes.isEmpty() && i <= unconsumedPrefixes.peekFirst()) { fillMode = prefixFillMode; } else { fillMode = FillMode.UNIFIED; } builder.breakOp(fillMode, "", ZERO, Optional.of(nameTag)); token("."); } BreakTag tyargTag = genSym(); dotExpressionUpToArgs(e, Optional.of(tyargTag)); if (!unconsumedPrefixes.isEmpty() && i == unconsumedPrefixes.peekFirst()) { builder.close(); unconsumedPrefixes.removeFirst(); } Indent tyargIndent = Indent.If.make(tyargTag, plusFour, ZERO); Indent argsIndent = Indent.If.make(nameTag, plusFour, trailingDereferences ? plusFour : ZERO); dotExpressionArgsAndParen(e, tyargIndent, argsIndent); needDot = true; } builder.close(); }
Example 18
Source File: Solution496.java From LeetCodeSolution with Apache License 2.0 | 4 votes |
/** * 1.关于复杂度 * 1.1 时间复杂度为O(m+n) * 1.2 空间负责度为O(n) * 2.我的解题思路 * 2.1 因为我们需要得到当前元素在nums2的下一个最大元素,所以我们可以构成一个当前元素与在在nums2的下一个最大元素的一对一映射 * 2.2 定义一个栈跟队列缓存结果 * 2.3 循环遍历nums2 * 2.3.1 如果当前栈不为空而且栈顶元素小于当前元素,将他们放入HashMap中 * 2.3.2 将当前元素入栈 * 2.4 遍历nums1获取HashMap对应的值 * 3.提交记录 * 3.1 力扣中耗时9ms,消耗37.8MB内存 * 3.2 leetcode中耗时2ms,消耗37.1MB内存 * 4.Q&A * * 1.About Complexity * 1.1 Time Complexity is O(m+n)(m is nums1.length,n is nums.length) * 1.2 Space Complexity is O(n) * 2.how I solve * 2.1 cache we need to mark next element on nums2,so it forms a one-to-one relationship with element on nums1 and bigger on element which bigger than element on nums2 * 2.2 define a stack and hashMap to cache calculate result * 2.3 circulate nums2 * 2.3.1 if stack is not empty,compare top element and current element,if current's is bigger than top's,put it to hashMap * 2.3.2 add current element to stack * 2.4 circulate nums1 and use current element to get value from HashMap * 3.About submit record * 3.1 9ms and 37.8MB memory in LeetCode China * 3.2 2ms and 37.1MB memory in LeetCode * 4.Q&A * @param nums1 * @param nums2 * @return */ public int[] nextGreaterElement(int[] nums1, int[] nums2) { Deque<Integer> stack=new LinkedList<>(); Map<Integer,Integer> map=new HashMap<>(); for(int temp:nums2){ while(stack.size()!=0&&stack.peekFirst()<temp){ map.put(stack.removeFirst(),temp); } stack.addFirst(temp); } map.forEach((key,value)->{ System.out.println(key+" "+value); }); int[] res=new int[nums1.length]; for(int i=0,length=res.length;i<length;i++){ res[i]=map.getOrDefault(nums1[i],-1); } return res; }
Example 19
Source File: AbstractFlinkClient.java From alchemy with Apache License 2.0 | 4 votes |
private Table registerSql(StreamTableEnvironment env, String sql, Map<String, TableSource> tableSources, Map<String, SourceDescriptor> sideSources) throws Exception { if (sideSources.isEmpty()) { return env.sqlQuery(sql); } Deque<SqlNode> deque = SideParser.parse(sql); SqlNode last; SqlSelect modifyNode = null; SqlNode fullNode = deque.peekFirst(); while ((last = deque.pollLast()) != null) { if (modifyNode != null) { SideParser.rewrite(last, modifyNode); modifyNode = null; } if (last.getKind() == SqlKind.SELECT) { SqlSelect sqlSelect = (SqlSelect) last; SqlNode selectFrom = sqlSelect.getFrom(); if (SqlKind.JOIN != selectFrom.getKind()) { continue; } SqlJoin sqlJoin = (SqlJoin) selectFrom; Alias sideAlias = SideParser.getTableName(sqlJoin.getRight()); Alias leftAlias = SideParser.getTableName(sqlJoin.getLeft()); if (isSide(sideSources.keySet(), leftAlias.getTable())) { throw new UnsupportedOperationException("side table must be right table"); } if (!isSide(sideSources.keySet(), sideAlias.getTable())) { continue; } DataStream<Row> dataStream = SideStream.buildStream(env, sqlSelect, leftAlias, sideAlias, sideSources.get(sideAlias.getTable())); Alias newTable = new Alias(leftAlias.getTable() + "_" + sideAlias.getTable(), leftAlias.getAlias() + "_" + sideAlias.getAlias()); if (!env.isRegistered(newTable.getTable())) { env.registerDataStream(newTable.getTable(), dataStream); } SqlSelect newSelect = SideParser.newSelect(sqlSelect, newTable.getTable(), newTable.getAlias(), false, true); modifyNode = newSelect; } } if (modifyNode != null) { return env.sqlQuery(modifyNode.toString()); } else { return env.sqlQuery(fullNode.toString()); } }
Example 20
Source File: FormData.java From quarkus-http with Apache License 2.0 | 4 votes |
public FormValue getFirst(String name) { final Deque<FormValue> deque = values.get(name); return deque == null ? null : deque.peekFirst(); }