I am trying to write a basic editor program and one of the parts asks me to "process dot commands that move point in whole line increments"
Earlier it says that a point is interpreted as specifying the location between characters rather than the characters themselves. and i need to use this to implements the following:
< moves point to the beginning of the document. > moves point to the end of the document. p moves point to the beginning of the previous line. n moves point to the beginning of the next line. k deletes the current line and leaves point at the beginning of the following line.
(there was a previous part before this so i already have some code that works) and in this part I'm trying to do a switch case
ie
for
< , >, p , n and k
I guess my question is how do i make this "point" need. Ive been using vectors, so the point needs to be somewhere inside the vector. I don't think ill be able to do what i need to do with out the point.
So, I have created a class called "point" and i have 4 "point" objects. They only have 2 variables, x and y (their position). The first 3 points form a triangle and now I need to tell if the forth one is inside or outside. I have found some solutions but they involve heavy math (they are based on the sum of the angles or something like that). I want to know if there is any way to solve this only by using the distance between points. I have created a function which takes 2 "point" objects and returns a float value which is their distance.
Here is some code:
#include <iostream> #include <cstdlib> #include <math.h> using namespace std;
In 2D I checked to see if a point was inside a shape by creating triangles between 2 neighbouring points and the centre of the object, then checking the angle to the 3 points from the test point and if the sum = 360... If not then it isn't inside the triangle. But how would I check if a point is inside a volume rather than an area? I know the same method would work but I don't think very well as it'll be testing with the thickness of the shell of the 3D object, which may be quite easily jumped in a single frame of movement..
And it compiles fine and, supposedly, works fine too, but when I try to put a break point inside the MakeTexture fuction gdb just goes crazy, it freezes and starts alocating memory until it reaches like 30+ mbs, and after that codeblocks freezes and I have to terminate the gdb process to return everything back to normal.
Now, another weird thing is that this only happens if I pass (char*)ilGetData(), if I pass something like NULL to the function, this doesn't happen.
This all compiles ok, but the last line in the code above causes a segmentation fault. I should mention Node is declared on its own in Node.h and what pgm is. including pgm.h in node.
I have a pretty big std::vector<matrix>, where matrix is a custom class defined by me. I would like to know how much memory has been allocated to that vector at a certain point in time. Is there any way of doing this in c++?
Or is my only shot, taking a look at the task monitor of windows/unix/whatever at execution time to estimate this?
What is another name for a Vector inside of a Vector. What is the name of this construct? Would it be a Constructor Vector? I think this is a trick question my teacher is asking...
I have one code that use MPI broadcast and I want to change it into Asynchronous Point to Point communication. I am newbie in Parallel programming. Looking for implementation of one simple same program in broadcast and P2P ?
How to output vector contents using the push_back function. My program reads in values just fine, but it does not output anything and I've been stuck on why.
here is my code:
#include <iostream> #include <array> #include <vector> using namespace std; int duplicate( vector < int > &vector1, const int value, const int counter)
I have a cpp app that reads in a number of files and writes revised output. The app doesn't seem to be able to open a file with a ' in the file name, such as,
N,N'-dimethylethylenediamine.mol
This is the function that opens the file :
Code: // opens mol file, reads in rows to string vector and returns vector vector<string> get_mol_file(string& filePath) { vector<string> mol_file; string new_mol_line; // create an input stream and open the mol file ifstream read_mol_input; read_mol_input.open( filePath.c_str() );
[Code] ....
The path to the file is passed as a cpp string and the c version is used to open the file. Do I need to handle this as a special case? It is possible that there could be " as well, parenthesis, etc.
I have asked a related question before, and it was resolved successfully. In the past, when I wanted to use std::max_element in order to find the maximum element (or even sort by using std::sort) of a vector of structures according to one of the members of the structure, all I had to do was to insert a specially designed comparison function as the third argument of the function std::max::element. But the latter comparison function naturally accepts two arguments internally.
For instance, here is a test program that successfully finds the maximum according to just one member of the structure:
And the output was this, as expected: Maximum element S.a of vector<S> vec is at: 9 [I]max element of vec.a between slot 3 and slot 6 is: 6, and its index is: 6 vec[6].a = 6 [I]max element of vec.a between slot 4 and slot 7 is: 7, and its index is: 7 vec[7].a = 7 [I]max element of vec.a between slot 5 and slot 8 is: 8, and its index is: 8 vec[8].a = 8 [I]max element of vec.a between slot 6 and slot 9 is: 9, and its index is: 9 vec[9].a = 9
However, I now need to search and find an element of vector<myStruct> according to just one member of myStruct, instead of finding the maximum or sorting as before. This presents a problem because the function std::find does not accept such a comparison function as its third argument.
This was the description of the std::find function that I found: find - C++ Reference
Code: template <class InputIterator, class T> InputIterator find (InputIterator first, InputIterator last, const T& val);
I could also find another function called std::find_if, but this only accepts a unary predicate like this: find_if - C++ Reference
Code: template <class InputIterator, class UnaryPredicate> InputIterator find_if (InputIterator first, InputIterator last, UnaryPredicate pred);
And once again this is either inadequate of I don't see how to use it directly, because for the third argument I would like to insert a function that takes two arguments with a syntax like this:
Code: int x=7; std::vector<S>::iterator result; result = std::find(vec.begin(), vec.end(), []( const (int x, const S & S_1) { return ( x == S_1.a ) ; } ) ;
Is there another std function that I can use to make search and find an element according to just one member of myStruct?
Or perhaps there is a clever way to pass two arguments to the unary predicate.
I don't know why this doesn't work. It doesn't return any errors, but it does the polynomial equation wrong. I tried using "^" instead of "pow" and it still does it wrong. I'm getting results like "-897123897" instead of "3". This is the code:
Code: #include <stdio.h> #include <conio.h> #include <math.h> int main() [code]....
I am reading about positive and negative infinity in c++ and i am trying to implement them in a fixed point math arthimethic implementation
I can see that max of a int will be equal to std::numeric_limits<int>::max(); and min value of the int will be equal to std::numeric_limits<int>::min(); in c++
Here as i am defining the int max and int min manually in my fixed point math implementation, my doubt is int min = -int max; or int min = -int max -1; ?
I am trying to print a matrix solution that I've stored in a vector of doubles. The original matrix was stored in a vector of vector of doubles. I want to print to the screen and an output file. Right now it just prints to screen column-style and the output file is horizontal-style. I tried to change the solution from vector of doubles to a vector of vector of doubles like the original matrix but when I run my code it crashes. Here is what I am referring to:
void readMatrix(vector<vector<double>> &matrix, vector<double> &b, int &N, string input) { ifstream in(input); in >> N; matrix.resize(N); b.resize(N);
[Code] ....
However when I change my printResult function to this (I removed the string argument because I just want to get it working to the screen first):
void printResult(vector<vector<double>> &sol, const int N) { //ofstream out(output); //int j; for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++){
[Code] ....
The program crashes. Am I even printing the matrix correctly?
I want to have it so that when i ask for the person witch item they want to drop on the ground it goes into another vector that i can pick back up the item if they want it back and erase when they walk away.
Why is it reading in nothing for the arrays, and also making the size of the total thing the total number of numbers? It should have a size of 2, not 5.
std::vector<unsigned char> vec1; //insert some values into vec1 std::vector<unsigned char> vec2;
Now I want to to copy 2 bytes from vec1 starting at index 5., why do i need to know how many bytes from the end of vec1?? can't i just specify how many bytes i want to copy from starting index?
If i do run the above program in turbo C/C++ complier, it outputs "h". But,if i change the code as i=0.6 and if (i<0.6), it outputs "w". Even if i change it to i=0.8 and if(i<0.8), then also it outputs "w".
In the above program, I am calculating the square of float number. But sometimes the number is entered as NAN and sometimes Output is NAN. What is NAN? I am entering floating point number, then y NAN is entered?
I have been writing a fixed point library the would handle fixed point numbers with an 8:24 whole/fraction ratio. This has been working quite well but since I have a 24 bit fractional part, it should be able to store 2^(-24).
Code: long long fraction_part = 0; long long divisor = 1;
The issue here is that since the smallest possible fraction is 2^(-24) the divisor could end up needing more than 64 bits and so won't work. I'm not quite sure how else I could do this.
I'm wondering about the point of pointers to functions. When is it used?I saw the below example. It doesn't make sense to me. I mean we can easily write code that does the same without having to use pointers.
Code:
#include <stdio.h> int addInt(int a, int b); // Adds 2 integers int add5to4(int (*function_pointer)(int, int)); int main(void) { int sum; int (*function_pointer)(int, int); }
