I am storing info in a vector but I want to store certain info at a particular index. I am new to using vectors and am unsure about have to do this. I am aware of the insert method but am confused on how to use it to store at a particular index.
View 1 RepliesI'm trying to make a function that lets me pass an index and a string and will insert the string at that index in the linkedlist... here is so function i have so far:
Code:
typedef struct node {
char* value;
struct node* next;
} LinkedList;
void llAddAtIndex(LinkedList** ll, char* value, int index) {
[Code] .....
I'm still trying to insert a node at a passed index in a linked list. This is my function, it doesn't work but i feel like it's close.
Code:
void llAddAtIndex(LinkedList** ll, char* value, int index) {
LinkedList* newNode = (LinkedList*)malloc(sizeof(LinkedList));
newNode->value = value;
LinkedList* prevNode = *ll;
for(int i = 0; i < index; i++){
[Code] ....
Create a program that will ask the user to input 10 integers of an array the program must write the index of the greatest element of the array
target output
input the integers
the greatest element is 5 and the index is 7
Here I have given my sample code, but it gave error. How can insert value in structure vector?
struct Hough_Transform_3D_Accumulator {
long int i;
long int j;
long int k;
long int count;
[Code] ....
Error Message:error C2661: 'std::vector<_Ty>::push_back' : no overloaded function takes 4 arguments
Here I have given my sample code, but it gave error. How can insert value in structure vector?
Code:
struct Hough_Transform_3D_Accumulator {
long int i;
long int j;
long int k;
long int count;
[code].....
Error Message:error C2661: 'std::vector<_Ty>:ush_back' : no overloaded function takes 4 arguments
I have vector of keyframes for animation:
struct Keyframe {
float time;// time in seconds
...
};
std::vector<Keyframe> vKeys;
And every loop i accumulate delta time to animate my object:
update(float deltaTime) {
timeRunning += deltaTime;
const float animationLen = 5.0f; // 5 seconds is total length of animation
...
To calculate current Key/index into vector i use:
float currTime = std::fmod(timeRunning, animationLen);
m_currKeyFrameInx = std::size_t(vKeys.size() * currTime / animationLen);
... use index
Can this logic fail?
Before i was using this:
float currTime = std::fmod(timeRunning, animationLen);
m_currKeyFrameInx = 0u;
for (std::size_t i = vKeys.size(); --i;) {
if (vKeys[i].time < currTime) {
m_currKeyFrameInx = i;
break;
}
}
Is it possible to pass the vector index '4' to the Height() function without passing it as a parameter of the function.
Basically, I'm trying to eliminate using 4 twice... what I'd LIKE the statement below to look like is this:
gx.Cell[4].Height();
The only way I can figure out how to get it to work is like this...
class grid{
public:
class CELL{
public:
int Height(int index); //returns the height of this cell
[Code] .....
how to check if a specific index equal to null when i try to implement it, it gives an error for example:
vector < vector <double> > v;
v[0].push_back(0);
v[0].push_back(1);
v[0].push_back(2);
v[0].push_back(3);
v[1].push_back(10);
v[1].push_back(11);
v[1].push_back(12);
v[1].push_back(13);
if(v[0][4]==NULL) {
cout<<"empty"<< endl;
}
I think std::copy appears to do what I'm looking for.
I'm in need of a vector member function that would allow me to "insert" a number of elements from one vector into another vector without resizing or destroying either.
An example of what I'm wanting to do is assign the contents of two[3-5][50-54] to one[7-9][2-6]. Other than looping through both vectors using .at(), is there a way to copy this?
This would be continuous within a user controlled loop with differing elements being exchanged.
typedef vector<vector<unsigned char> > vec;
vec one(10, vector<unsigned char>(10, '1')),
two(90, vector<unsigned char>(90, '2'));
I am trying to pop the element on a vector off and return its value at the same time
vector.push_back();
Unfortunately that code only removes that element from the vector it does not return it
Is the only way to get the element and destroy it is to do this?
vector.back();
vector.pop_back();
How to access an element of the point3f vector. E.g. :
int main() {
vector<Point3f> a;
a.push_back(Point3f(0,0,0);
a.push_back(Point3f(0,0,1);
//print first x,y,z element
cout<<a[0]<<endl;
[Code] ...
But it doesn't work firstly because it says can't use typename i.e. <float>
pop_back just returns void, so I just can't use that?
erase is okay but it doesn't return anything....
Do I use a combination of both?
How could I search a vector element with multiple strings
i.e. vector.at(i) = This is a test
How could I search that to look for the word "test" in that element?
Consider I have a vector of strings and then I use an istringstream to read each word of each element in the vector, why do I nescessarily use an istringstream?
This is the code that does what I just described (I think)..
Code:
for(auto &elem : svec) {
istringstream strm(elem);
while (strm >> word)
//Magic
}
What would be the equivalent of using something else than an istringstream in this scenario and how does the istringstream work?
I am programming a 2-D platformer video game. The stages are composed of an array (really a vector) of 16x16 px^2 tiles. I have defined a base class "Tile" and several derived classes, e.g., "Ramp", "Door", etc., which have their own attributes. The idea is that upon entering a room, the program will load all of the necessary tile data for that room into a vector. So, I have a vector that looks like: vector <Tile*> room_tiles, and resize it based on the total number of tiles in the room: room_tiles.resize(Tile_Count). I then want to read in certain info from the data file containing all of the tile information for that room. For example, if the data file says Tile 5 should be a ramp, I want to change the 5th element of the room_tiles vector to the derived ramp class. This is really where I'm having trouble. I've worked with vectors of base and derived classes before, but those were always of indeterminate size and I always used something like: (Vector).push_back(new DerivedClass()) to specify the derived class of that element. The problem is that that method only seems to work if you are appending elements to the end of a vector.
how I can do this?
I'm having a problem filling a vector from a file. Basically, it is adding an empty element at the end. I'm new to Qt and haven't worked with file streams much so how to stop the stream before it adds the extra element.
void gui::get_data() {
mileage.clear();
QFile file(file_label->text() + ".txt");
QTextStream in(& file);
float m;
float g;
QString d;
[Code] ....
But, if I add another element to the vector and write that the file look like this.
//file after adding element
132654 0 02132014
132654 0 02132014
0 0
132998 22 02202014
I have it set to append at the moment so that is why the first line is repeated. I figure the problem is with if(in.atEnd()). I could fix it by deleting the last element right after adding it, but that seems like more of a hack than anything else.
I have a vector of int,
Code:
vector<int> row_numbers{1,2,3,4,5,6,7,8,9};
I want to sequentially remove one element at a time starting with the first. When the second element is removed, the first element needs to go back in. The sequence would look like
Code:
// original vector, row_numbers.size()=9
row_numbers{1,2,3,4,5,6,7,8,9};
// trimmed vector, row_numbers_trim.size()=8
[Code] .......
I have been working under the assumption that the best method would be to have row_numbers remain untouched and work on a copy. For each step in the sequence, you would create row_numbers_trim as a copy of row_numbers, and then remove an element from row_numbers_trim.
Code:
// position being removed
int counter = 0;
// copy original vector
row_numbers_trim = row_numbers;
// remove the first element from the copy
row_numbers_trim(row_numbers_trim.begin()+counter);
All you would have to do here is to increment counter in a loop. is there a better way?
I have N vectors which look like this:
[1→m] [m+1→2m] [2m+1→3m] [3m+1→4m] [4m+1→5m]..... [{(N-1)m}+1→Nm]
I want to select 1 element from each vector without duplication of any combinations. Essentially only when all combinations are done with 1st element in first vector ,only then it should move to next element in first vector.
Say i have elements :[123] [456] [789]
my combinations should be like
147
148
149
157
158
159
167
168
169
247....
Also, I cant have any repetitions and only after all combinations of 1 are done only then the loop has to move to next combination ie 247 combination and so on.
I tried NCK (n choose k) command but it gave me random combinations. How should i go about it with using minimal for loops?
how to insert a variable for the size of array and prompt user to insert the elements for the array?
View 13 Replies View RelatedSo I have linked list and function which deletes element if next element is bigger, so my code is working but its not working with first element, in the comment I have wrote code which I would code for checking that first element, but when ever I check it is blowing up all program.
#include <iostream>
using namespace std;
struct llist {
int x;
llist *next;
[Code] .....
I have a global list that contains smaller lists of char arrays. I have an issue where when I'm reading back the inner lists the last element of one list seems to point to first element of the next.
So my data looks like the below (values separated by commas with the pairs separated by tabs. The last pair in a line is the same as the first). When I read the first list back instead of seeing "456.678,678.98" as the last element in the list. I see "435.67,234.98" twice: at the end of the first list and start of the other. I have debugged when the list is populated and can see the correct values going in so I can't figure what's happening.
456.678,678.98 123.45,345.56 256.67,789.98 456.678,678.98
435.67,234.98 123.65,342.56 987.78,678.34 435.67,234.98
Code to fill the list:
obstacle_list = op_prg_list_create();
while (fgets(line, sizeof(line), obstaclePositions_traj_file) ) {
token = strtok(line, "
"); //Pull the string apart into tokens using the
input = op_prg_list_create();
[Code] ....
I have an std list of type double.. and the list is always guaranteed to have just 2 elements. I need to get the value of element 2 minus element 1. What is the least amount of code to accomplish that?
I tried this:
Code:
list<double> dList;
dList.push_back(1.0);
dList.push_back(2.0);
list<double>::iterator iter = dList.begin();
list<double>::iterator iter2 = dList.end();
double result = *iter2 - *iter;
But this code does not work. Why not?
I was trying to debug a code which was behaving in an abnormal way
Code:
#define NOOFELEMENTS 32
unsigned char array[NOOFELEMENTS];
unsigned char array1[23];
init() {
for(i=0;i<=32;i++)
{
array[NOOFELEMENTS] = 0
}
}
I could trace the above one of the mistakes where the array initialization is crossing the array limits and writing into array[32] which is not available. My question does it overwrite into array1 as it is declared below array or it can write into any other location.
I am trying to get the index of a value by inputting the value:
For example if i have
int arr[5]={22, 85, 58, 78, 69};
indexOfItem(arr, 78);
and have the output be:
the index of the item is: 3
If i have current index and row/columns count how do i get on which row and on which column index is individually?
This is what i have tried, but column index is incorrect:
#include <iostream>
int main()
{
int rows = 5;
int colm = 6;
int inx = 12;
int rowInx = inx % rows;
int colInx = inx % colm;
std::cout << "row: " << rowInx << std::endl;
std::cout << "col: " << colInx << std::endl;
return 0;
}