stack

Why did C never implement “stack extension”?

由 Deadly 提交于 2019-12-23 04:22:26
问题 Why did C never implement "stack extension" to allow (dynamically-sized) stack variables of a callee function to be referenced from the caller? This could work by extending the caller's stack frame to include the "dynamically-returned" variables from the callee's stack frame. (You could, but shouldn't, implement this with alloca from the caller - it may not survive optimisation.) e.g. If I wanted to return the dynamically-size string "e", the implementation could be: --+---+-----+ | a | b | -

C++ Calculator using Stacks and Queues

由 試著忘記壹切 提交于 2019-12-23 01:52:13
问题 I'm trying to understand a topic in class about using stacks and queues as a means of programming a calculator. I understand what infix and postfix expression is but how does it make it easier for a program to evaluate an expression and why are queues and stacks ideal in this situation? Thanks 回答1: It makes the order of operations simpler to handle, for example: + * - 4 2 5 3 Can only mean ((4 - 2) * 5) + 3 Which might be more readable for us, but we need to know the order of operations and

C++ STL stack pop operation giving segmentation fault

由 一曲冷凌霜 提交于 2019-12-23 01:50:05
问题 I implemented a programming question from this link in C++ but I am getting a segmentation fault in the pop() operation with my code. I am fairly new to C++ and can not seem to find the error myself. #include<iostream> #include<stack> using namespace std; void printNge(int *arr); int main() { int arr[] = {1,4,2,6,3,8,7,2,6}; printNge(arr); return 0; } void printNge(int *arr) { stack<int> st; st.push(arr[0]); for(int i=1; i<9;i++) { while((st.top() < arr[i]) && (!st.empty())) { cout <<

Clear backstack in Android pre Honeycomb?

由 こ雲淡風輕ζ 提交于 2019-12-22 18:42:55
问题 Is there an easy way or another workaround to delete the backstack in Android pre Honeycomb(before API level 11)? People suggest using the FLAG_ACTIVITY_CLEAR_TOP in conjunction with FLAG_ACTIVITY_NEW_TASK when starting a new activity, but this does only delete the stack on top of my current position, not the stack under my position. It should not be that hard to start from a fresh task. Some ideas around this? I can not use FLAG_ACTIVITY_CLEAR_TASK because I need to support those versions

Direct stack and heap access; Virtual- or hardware- level?

由 一个人想着一个人 提交于 2019-12-22 14:58:42
问题 When I'm on SO I read a lot of comments guiding (Especially in C) "dynamic allocation allways goes to the heap, automatic allocation on the stack" But especially regarding to plain C I disaggree with that. As the ISO/IEC9899 doesn't even drop a word of heap or stack. It just mentions three storage duriations (static, automatic, and allocated) and advises how each of them has to be treat. What would give a compiler the option to do it even wise versa if it would like to. So my question is: Are

新手，正在学Java Collection，瞎写点东西-一个基于链表的stack及其遍历

由 |▌冷眼眸甩不掉的悲伤 提交于 2019-12-22 11:42:36
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> import java.util.Iterator; public class LinkedStack<U> { private class Node<T> { T data; Node<T> next; Node() { data = null; next = null; } Node(T data, Node<T> next) { this.data = data; this.next = next; } boolean end() { return data == null && next == null; } } private Node<U> top = new Node<U>(); public U pop() { U result = top.data; if (!top.end()) top = top.next; return result; } public void push(U data) { top = new Node<U>(data, top); } public Iterator<U> iterator() { return new Iterator<U>() { public boolean hasNext() { return !top.end(); } public U

html stack order

由 流过昼夜 提交于 2019-12-22 10:11:08
问题 Consider the following code: <!DOCTYPE html> <html lang="en"> <head> <title>HTML</title> <meta charset="utf-8" /> <style type="text/css"> h1 { font-size: 2em; font-family: Verdana; font-weight: bold; } p { border: 3px solid blue; margin-top: -50px; background-color: green; color: white; } </style> </head> <body> <h1>QUESTION</h1> <p>The header text in the preceding h1 element is behind this paragraph's text (as expected), but on top of this paragraph's background and border (not expected). <

How does the compiler determine the needed stack size for a function with compiler generated temporaries?

由 ≯℡__Kan透↙ 提交于 2019-12-22 08:55:52
问题 Consider following code: class cFoo { private: int m1; char m2; public: int doSomething1(); int doSomething2(); int doSomething3(); } class cBar { private: cFoo mFoo; public: cFoo getFoo(){ return mFoo; } } void some_function_in_the_callstack_hierarchy(cBar aBar) { int test1 = aBar.getFoo().doSomething1(); int test2 = aBar.getFoo().doSomething2(); ... } In the line where getFoo() is called the compiler will generate a temporary object of cFoo, to be able to call doSomething1(). Does the

How to control space between stack bars in ggplot2?

由 走远了吗. 提交于 2019-12-22 08:11:21
问题 I'm plotting a stack barplot in ggplot2. My dataset is like, var1 var2 var3 value treatment1 group_1 C8.0 0.010056478 treatment2 group_1 C8.0 0.009382918 treatment3 group_2 C8.0 0.003014983 treatment4 group_2 C8.0 0.005349631 treatment5 group_2 C8.0 0.005349631 var1 contains 5 treatments, these five treatments belong to two groups in var2 , and each treatment has 14 measurements in var3 , their value stored in value . I want to make a plot to compare these five treatments, and their

Where does exception object have its space, heap or stack, and how to access it in different class?

由 半腔热情 提交于 2019-12-22 07:49:21
问题 Recently an interviewer asked me where the exception object in C++ is allocated, heap or stack? I'm not sure but I answered stack since I thought there is no "new" or "malloc". Is it correct? Then he kept asking me that if it's on stack, assuming class A throw a exception object, let's say "e", and class B catch "e". Since "e" is on the stack of A, then how does B can have the access to this "e"? I'm not very clear about the second question. Could anyone can give me some example code showing
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