I've come to a point in tuning my algorithm, where I need to sum the elements of two arrays, eg.:
array1: (1,1,1)
array2: (2,2,2)
arrayOut: (3,3,3)
Is there any way how to do that without need to iterate? Some memory hacks?
I need to use dynamic memory allocation and use pointers to iterate through the arrays that I have already in this program. I am lost, nothing I do works and where to use the pointers. I am just looking for a push in the right direction so I can finish this project and how I can implement pointers in my program.
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
#include <stdio.h>
using namespace std;
[Code]...
Compiled on turbocpp 4.5.....error is that the final merged array is much bigger with garbage values...
Code:
//cpp program to concatenate 2 arrays
#include<iostream.h>
#include<conio.h>
//the class
class array
[Code] .....
I have been trying to merge the two arrays in merge sort but I am not able to do so. I am getting only half of the array.
Code:
int i,j,k,a[100],n,temp;
printf("Enter array size: ");
scanf(" %d",&n);
printf("
Enter the numbers:");
[Code] ....
I'm trying to write a code that takes two arrays from the user (presumably in ascending order) and then passes the sizes of both arrays and a pointer to each to a separate "int* mergeArrays" function that will merge sort the two. I've written a lot of the code, but I can't get it to compile. I get errors: lab6.c: In function "main":
lab6.c:31:14: error: expected expression before "int"
mergeArrays(int* firstArray, int size1, int* secondArray, int size2);
^
lab6.c:31:14: error: too few arguments to function "mergeArrays"
[Code] ....
I need to write a function that will merge the content of two sorted arrays of type double values. The function should not assume that both its input parameter arrays are the same length.
Here is my program so far - I know there is alot of errors and mistakes:
Code:
#include<stdio.h>
void merge(int firstArray[],int secondArray[],int size) {
int mergedArray[size],i=0,j=0,k=0;
while(i<size||j<size) {
if(i==size) {
[Code]...
So I have a vector that I want to iterate through randomly, and by random I mean that each element is only accessed once but I don't want to shuffle the vector because the vector elements are large. So I want this functionality:
std::vector<SomeLargeObjectWithoutACopyConstructor> myvec;
// ...fill myvec
std::random_shuffle(myvec.begin(),myvec.end());
for (auto& value : myvec)
{
// do stuff
}
Only I don't want to do this because the object type has no copy constructor and is large, so I don't want to shuffle the vector, just the iteration path. Is there a simple and efficient way of iterating randomly through a vector while ensuring that each object is only accessed once?
How can I use one index to iterate between all the values
for example:
//I defined
vector<typeA> VA(XD,typeA());
vector<typeB> VB(XD,typeB());
//then the standard method to iterate is:
for(vector<typeA>::Size_type i=0; i<VA.size(); i++) {
VA[i].functionA();
VB[i].functionB();
}
the other way, use int,
//I defined
vector<typeA> VA(XD,typeA());
vector<typeB> VB(XD,typeB());
//then the standard method to iterate is:
for(int i=0; i<VA.size(); i++) {
VA[i].functionA();
VB[i].functionB();
}
none of above make me feel formal...
How do I iterate through a two dimensional vector? To iterate through and print the elements of a single dimensional vector I use:
vector<int> a;
for(vector<int>::iterator it=a.begin();it<a.end();it++)
cout<<*it;
How do I do the same for a two dimensional Vector?
so i have a container called Source that is of type std::map<std::string, std::vector<std::string>> but when I try to print it with this function:
void Lexer::PrintSource()
{
for(auto Iterator = this->Source.begin(); Iterator != this->Source.end(); Iterator++)
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
cout<< *SubIterator << endl;
}
i get these errors:
Lexer.cpp: In member function 'void Lexer::PrintSource()':
Lexer.cpp:29:42: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'begin'
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
^
Lexer.cpp:29:76: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'end'
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
^
How can a set a pointer , to a matrix example matrix[20][20] and iterate ( loop ) in each row first sort of X first and then Y through it using the pointer , how to setup dynamic allocation
through pointer = new matrix[20][20]
and finally call delete on pointer when done with the matrix.
I need to allow the user to input an integer of any length and print out the word of each number in the integer. So the user would enter "324562" and then the output would be "three two four five six two". I'm struggling to understand the best way to do it in C. I know I need a loop that goes through the int but I don't know how to do it
View 7 Replies View Related I need to iterate through a vector in a const function, and, as my function is called very often, to get more performances I need my iterator to be declared somewhere else than the function, so it doesn't have to get deleted and recreated over and over again. So here is my code:
class Shop {
public:
//methods
virtual void draw(sf::RenderTarget &target, sf::RenderStates states) const{
[Code] ....
Seems great? Well no. I actually get an error on the "for" line.
It tells me : "You can't use '=' here" and "You can't use the ++ operator here"
The thing is, if I actually declare my iterator in the loop, the compiler stops giving me warnings, but, as I said, I really want to avoid doing that.
A C++ container type called std::map is used to store elements that are formed by a combination of key value and mapped value. How do you iterate through this container and find the value mapped to a specific key?
View 3 Replies View RelatedThe example enable a client to iterate the internal std::vector using being() and end().
Code:
class foo {
public:
typedef std::vector<std::string>const_iterator iter;
iter begin () const;
iter end () const;
[Code] .....
In the future I see the need for this class to be able to control sequence (sorting) and also show a subset of the complete list based on a search parameter.
Using std::sort appear to solve the ability to sort the collection.
How can I return an iterator to the client which only iterates a sub-set of all items in the std::vector?
An example would be, I add this method to the class;
Code:
void find(const std::string& st);
So if the client performs (below) only items in std::vector that contains the character "a" should be possible to iterate.
Code:
foo f;
f.search("a");
One option would be to operate with two collection inside the foo class. One more static containing all items and the other containing the sorted and filtered items. This would lead to some copying but should work. Far from perfect.
I'm having trouble getting my loop to work correctly. If I iterate the for loop once it works as expected and displays proper output. When I try to iterate two times or more the program gets stuck in an infinite loop.
testData8.dat:
Code:
12 9
13 756
So I have an issue with a homework assignment that I am coding. I am attempting to get a function to iterate through an array and search for a number that was stored in an array by the user. So far I can take the number, get the numbers displayed but in my menuChoice2 function, for some reason the program is not confirming whether or not the number is entered, and is only telling me that the number has not been found, instead of confirming that the number is in the array.
Here is my code thusfar:
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
// Variables that are Globally declared
int menuChoice = 0;
int usernum[1000] = { ' ' };
[Code] .....
To be clear I am not getting any errors but something is telling me that the error is in the formatting of menuChoice2.
So I have this problem with not being able to iterate over a vector in a nested for-loop. Here's the nested for-loop:
bool innerHit = false;
for (std::vector<Sprite*>::iterator outerIter = sprites.begin(); outerIter != sprites.end() && (!sprites.empty()); outerIter++) {
Sprite* spriteOne = *outerIter;
for (std::vector<Sprite*>::reverse_iterator innerIter = sprites.rbegin(); innerIter != sprites.rend() && (!sprites.empty()); innerIter++) {
Sprite* spriteTwo = *innerIter;
[Code] .....
What happens is, after having called the collisionDestroy-function and the program tries to execute the nest loop in the outer for-loop, it all crashes with the text "Expression: vector iterator not decrementable", which I understand is because the iterator will have already become useless. The question is: know this, how do I fix it? I can't seem to get a hang of it.
Here's the collisionDestroy-function (the collisionReaction does nothing but sets a few local variables):
void Enemy::collisionDestroy(std::vector<Sprite*>& sprites) {
for (std::vector<Sprite*>::iterator iter = sprites.begin(); iter != sprites.end(); iter++) {
Enemy* tmp = dynamic_cast<Enemy*>(*iter);
if (this == tmp && collisionType == 3 || collisionType == 1) {
sprites.erase(iter);
break;
}
}
}
I am trying to iterate a matrix in order to exchange rows and columns element by element. Although the function that exchanges the rows has come out well, i don't seem to figure out how to do the same on columns.The columns switch for a matrix like
1 2 3
1 2 3
1 2 3
if i try to switch column 3 and 2,is:
1 3 2
1 3 2
1 2 3
Here are both of the functions:
void interchange_rows(int *p,int n,int r1,int r2){
int temp;
for(int i=0;i<n;i++){
temp=*(p+r1*n+i);
*(p+r1*n+i)=*(p+r2*n+i);
*(p+r2*n+i)=temp;
[Code] ......
I am trying to write a loop that will iterate through a char array in C and pull the IP addresses and test them to see if they respond. My ultimate goal is to have the first one that responds returned in the function, but the loop is not running correctly. It will run through right the first time, but then will start over again.
Code:
const char * getServer(char *svrList) {
char *srList;
srList = strtok(svrList, " ," );
printf("Contents of srList b4 loop: %s
", srList);
printf("Server List: %s
", svrList);
[Code] ....
Code output:
Contents of srList b4 loop: 1.1.1.1
Server List: 1.1.1.1
result is "1.1.1.1"
Hitting else loop
Contents of srList in else: 2.2.2.2
result is "2.2.2.2"
result is "2.2.2.2"
Contents of srList b4 loop: 1.1.1.1
Server List: 1.1.1.1
result is "1.1.1.1"
Hitting else loop
Contents of srList in else: (null)
i can't seem to get this merge sort to work. running through gdb though;
Code:
*Filename: mergeSort.c
*Usage: This implements merge sort algorithm to sort and array of numbers.
*/
#include <stdio.h>
#include <stdlib.h>
}
[code]...
Code:
/* Mergesort: Use merge() to sort an array of size n */
#include <stdio.h>
#include <stdlib.h>
void mergesort(int key[], int n) {
int j, k, m, *w;
for (m = 1; m < n; m *= 2)
[Code] .....
Question : Modify mergesort() so that it can be used with an array of any size, not just with a size that is a power of two. Recall that any positive integer can be expressed as a sum of powers of two. For example,
27 = 16 + 8 + 2 + 1
Consider the array as a collection of subarrays of sizes that are powers of two. Sort the subarrays and then use merge() to produce the final sorted array.
I tried so many algorithms and all failed!! What i dont know is how to create subarrays ?
My programs gives a segmentation fault for large n (n=9999999). It works fine for small n. Where n = total numbers to sort
List<long>* Merge(List<long> *ParentList)
{
if(ParentList->length()==1)
{
[Code]....
#include<stdio.h>
#include<stdlib.h>
#include<sys/time.h>
#include<time.h>
#include<math.h>
typedefstruct points{
float axis[2];
[Code] .....
I am attempting to merge binary files. However, this is to no avail. The program keeps segfaulting. I want to merge the buffers the files are stored in and then write the new one to disk. Anyway, here is my code.
Main.cpp:
#include "getsize.h"
long lSize;
char * buffer;
size_t result;
FILE * pFile;
FILE * pFile2;
FILE * pFile3;
void read1() {
pFile = fopen ( "uTorrent.exe", "rb");
[Code] ....
I tried to keep the coding style as similar as possible. I tested these with 4 million (4x1024x1024) 64 bit unsigned integers, Visual Studio 2005, 64 bit mode, Win XP X64, Intel 2600K 3.4ghz cpu. The average time for top down = 3.7 seconds, bottom up = 3.5 seconds.
Code: // tsorttd.h - top down merge sort
template <class T>
T * TopDownMergeSort(T a[], T b[], size_t n) {
TopDownMergeSortAtoA(a, b, 0, n);
[Code]....