C++ :: Sort Particular Column Of CSV File
Apr 6, 2013I need sorting a particular column (column 1) of a .cvs file (the file has 10 columns) by alphabetic order. How I can accomplish this ?
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C++ :: Column Based Database - Constructing Very Fast Radix Sort
Apr 12, 2014I'm attempting to build a column based database, and I'm new to C++ (just wanted to play around with building a column base database "for the fun of it"). I want to construct a very fast radix sort, that would allow me to quickly sort groups of columns based on integer values. My general preference is to take up more RAM to get more performance.
I'd like to build the radix sort by allowing 256 "buckets" to drop values in as I'm sorting. This allows me to sort through a group of 4 byte integers in only 4 passes. But assuming I'm trying to sort a large group of values (say 50+ million), I'm not sure what type of container to use for these. Also note I'm pretty unfamiliar with the "standard library", so below are my thoughts:
Vectors:
-Pros: Easy to use, and very fast for sequential and random access inserts / reads
-Cons: If they have to dynamically resize because a given vector wasn't large enough, this can apparently really slow performance. Unless I make another pass over the numbers before I start sorting, I wouldn't know how big to make individual the individual vectors. This means I either have to make them "too big" and waste space, or pay a performance price for either resizing, or scanning data first.
Lists:
-Pros: Seems like I wouldn't have to specify size ahead of time, so I could just easily insert values to a given list. Also, since I don't need random access reads (I'll ready the "0" list sequentially, then the "1" list, etc. they should work fine.
-Cons: I don't really know much about lists, but I'm not sure how easy it is to append a new value to the end of a list. I've read that standard library lists include both "forward" and "backward" pointers, which I don't need. Also, I find it hard to believe that there isn't some time taken up with memory allocation. If I build a list and append x million records in it, is it calling memory allocation routines x million times?
Or maybe there's another container type I should learn?
Again, my goal is to make this "fast", not "memory efficient". But having said that, the fastest way I could think of (use 256 vectors, each sized equal to the total number of members to be sorted) is just too much memory to burn - 256 times a vector big enough to hold millions of elements is too much.
C# :: How To Get Column Names From Db3 File
Oct 2, 2014I have .db3 file, and he has 14 tables,and every table has certain number of columns. Example i have table called "BASIC_INFO" and that table has columns "First Name", "Last Name" and "Age".
How can i get name of table and name of every column,so if i some day add column "Male" i get name of this column too. I need first to calculate number of columns,put that in some integer, and then for example create string array which will contain : array[0] = "First Name" ,array[1] = "Last Name"...
SQLiteConnection myConn = new SQLiteConnection("Data Source=" + DB3Path + ";Version=3;New=False;Compress=True;");
//string query = "Select * From " + DB3Path + ".INFORMATION_SCHEMA.COLUMNS";
string query = "Select * From BASIC_INFO.INFORMATION_SCHEMA.COLUMNS;";
SQLiteCommand sqCommand = new SQLiteCommand(query);
[Code] ....
I tried this too:
string query = "select * from INFORMATION_SCHEMA.COLUMNS"
+ "where TABLE_Name='BASIC_INFO'"
+ "order by ORDINAL_POSITION;";
string query = "SELECT TOP 0 * FROM BASIC_INFO";
C/C++ :: How To Read Specific Column From A File
Nov 21, 2013I have a .txt file which contains 121 lines,now I want to read the no 20 columns from that file. How to read it. I have tried the following code.
my c.txt file look like following :
A B C D E.....AAA
#include<stdio.h>
#include "conio.h"
#include "string.h"
int main() {
FILE *fp;
char a2[500];
[Code] ....
C :: Find The Maximum Value In A Column Of Text File
Jul 28, 2014I have problem with finding the maximum value in a column. This is my code
Code:
#include <stdio.h>
#include <stdlib.h>
int main() {
FILE *fp;
fp = fopen ("C:
ocket1.txt", "r");
float time, altitude, velocity, acceleration, amax, bmax;
[Code] ....
The first loop will print out all of numbers in the velocity column. The second while loop is looking for the maximum value in that column. It is supposed to print out the max velocity in the end of the second loop. However, when I build and run the program, it's crashed. I run debugger and received "Segmentation fault" error. When I eliminate the second loop, it run just fine I use Code::Block for text editor.
C :: Reading Values From File To First 2 Columns Of 2D Array / Assigning 0 To 3rd Column
Apr 4, 2014I am attempting to read values from a file into a 2d array temp[31][2] (31 rows, 3 columns).I only want the values from the file to be read into the first two columns.I believe I am accomplishing that but when I go to print the array, I expect the first two columns to have the file data and the third column to have all zeros. The third column, however is printing such that the value is the next row/first column.
I'm not sure for instance why on the bottom loop for line 1 it doesn't print:
temp[0][0] temp[0][1] temp[0][2] 20 49 0 It instead prints: 20 49 1
Code:
#include <stdio.h> Code: #include <math.h>
FILE *inptr;
int main() {
int temp[31][2] = {0}, tempavg[31][2] = {0};
int i, j, k, sum;
inptr = fopen("ProgrammingProject14.txt", "r");
[code]....
C Sharp :: Listbox Item Display - How To Add Column From File To Combobox
Oct 4, 2012How to display the item in listbox,which are selected from three combobox.
View 1 Replies View RelatedC :: Radix Sort Function To Sort Array Of 64 Bit Unsigned Integers
Aug 19, 2013Example radix sort function to sort an array of 64 bit unsigned integers. To allow for variable bin sizes, the array is scanned one time to create a matrix of 8 histograms of 256 counts each, corresponding to the number of instances of each possible 8 bit value in the 8 bytes of each integer, and the histograms are then converted into indices by summing the histograms counts. Then a radix sort is performed using the matrix of indices, post incrementing each index as it is used.
Code:
typedef unsigned long long UI64;
typedef unsigned long long *PUI64;
PUI64 RadixSort(PUI64 pData, PUI64 pTemp, size_t count) {
size_t mIndex[8][256] = {0};
/* index matrix */
PUI64 pDst, pSrc, pTmp;
size_t i,j,m,n;
UI64 u;
[Code]....
C++ :: Merge Sort Between 2 File With Thread
May 29, 2014// mergefile2norecreation.cpp : definisce il punto di ingresso dell'applicazione console.
//
// Filemerge.cpp : definisce il punto di ingresso dell'applicazione console.
//
#include "stdafx.h"
int _tmain(int argc, _TCHAR* argv[]) {
TCHAR inputfile1[MAX_PATH];
TCHAR inputfile2[MAX_PATH];
TCHAR outputfile[MAX_PATH];
[Code] .....
There is a smart way to make a merge sort between 2 file already ordered? I had try it ,and above there is my result,it works but i think that it's possible to do it in a smart way...
C++ :: How To Bubble Sort Data From A File
Sep 26, 2014I'm trying to write a program that will print the data of 10 records from a file and then, sort them descending to ascending by year.
Here are the records:
NameYearTuition
David20111582.38
Sylvester2012728.82
Ben19920
Brandon1995500.25
Riley1997845.19
Mark2009700.05
Roberts2002450.87
Butler2005920.78
Steve20001000.00
Joe19941200.15
Here is my code so far:
#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main () {
string line;
[Code] ....
How do I go about arranging it?
C/C++ :: Merge-Sort With X And Y Coord From File
Apr 17, 2014So I have a file with 2 float numbers like this
0.041631 0.176643
0.364602 0.091331
0.092298 0.487217
0.526750 0.454433
0.233178 0.831292
0.931731 0.568060
0.556094 0.050832
0.767051 0.018915
0.252360 0.298197
0.875981 0.531557
I would like to place the first column in one array and second in another. I am using the merge sort and merge algorithm from my book to sort the first column (x-coord) in descending order and the second column (y-coord) in ascending order. The output would look like this.
(where, x, y)
6: 0.931731 0.018915
10: 0.875981 0.050832
8: 0.767051 0.091331
7: 0.556094 0.176643
4: 0.526750 0.298197
2: 0.364602 0.454433
9: 0.252360 0.487217
5: 0.233178 0.531557
3: 0.092298 0.568060
1: 0.041631 0.831292
I am ignoring the where(line number) for now. The error I get is: cannot convert 'points_struct*' to 'int*' for argument '1' to 'int mergesort(int*, int, int)'.
So my question is how to get my points_struct arrays to work with the algorithm I have from book. Here is what I have so far.
#include<iostream>
#include<fstream>
using namespace std;
[Code].....
C/C++ :: How To Bubble Sort Data From A File
Sep 26, 2014I'm trying to write a program that will print the data of 10 records from a file and then, sort them descending to ascending by year.
Here are the records:
NameYearTuition
David20111582.38
Sylvester2012728.82
[Code].....
C++ :: Sort Text File By First Number Of The Line
Dec 24, 2013I have a text file like this
0 1 2 C
10 1 2 S
7 1 2 C
11 1 2 S
9 3 43 C
10 3 43 S
1 3 43 C
101 3 43 S
with this code
ifstream in("fout2.txt");
if (in) {
vector<string> lines;
string line;
while (getline(in, line))
[Code] ....
I obtain this result
0 1 2 C
1 3 43 C
10 1 2 S
10 3 43 S
11 1 2 S
101 3 43 S
7 1 2 C
9 3 43 C
but i want a result like this :
0 1 2 C
1 3 43 C
7 1 2 C
9 3 43 C
10 1 2 S
10 3 43 S
11 1 2 S
101 3 43 S
C++ :: Read In A TXT File And Sort It By SSN In Ascending Order
Jan 25, 2014So I need to read in a .txt file and sort it by SSN in ascending order. How to start this but here's what I have so far:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
struct Information {
char name[25];
long SSN;
[Code] .....
Also here is the contents of the .txt file:
Matthews,Jocob
459237148
19
3930 4th Blvd, Yourcity, NJ 88710
......
and so on.
C/C++ :: Sort Word Length From A Text File
Mar 23, 2014I was asked to create a program to find word frequencies, word length in a text file. I am able to use map to do the frequencies part but don't know how to sort the the output accordingly to the length of the words. The example output that I should get is
1 a. 362
i. 157
2 an. 122
at. 201
3 add. 2
age. 1
int main(void) {
static const char* file = "demo.txt";
map<string, unsigned int> wcount; {
ifstream fileStream(file);
[Code] .....
C/C++ :: Sorting Deck From File With Merge Sort
Nov 27, 2014I'm trying to sort a deck from file with merge sort.I have all my code working except merge sort function .
#include<iostream>
#include<fstream>
#include<stdlib.h>
#include<stdio.h>
using namespace std;
int temp;
int br = 1;
[Code] ....
C :: Open Multiple File And Sort Them Using Function Prototype
Apr 9, 2013I am quite new to C programming. Now facing lots of problem with the code below. I attempt to convert he alphabet sorting into function prototype model but still facing warning during compilation.
Besides, I wish to open multiple file at the same time as well using array looping method, but got no idea to modify it...
[URL] ....
Code:
#include <stdio.h>
#include <string.h>
#define SIZE 255
#define LEN 31
// Function prototype
void alphabetisation (int final, char *webaddress[]);
[Code] .....
C++ :: Radix Sort Program Implementation On Main CPP File
May 11, 2014I'm having trouble implementing my radix sort program on the main .cpp file. Here is what the radix header file looks like::
#include <vector>
#include <queue>
using namespace std;
void distribute(const vector<int> &v, queue<int> digitQueue[], int pwr) {
int i;
for(int i=0; i < v.size(); i++)
digitQueue[(v[i]/pwr) % 10].push(v[i]);
[Code] .....
Here is what my main looks like:
#include <iostream>
#include <cstdlib>
#include <vector>
#include <queue>
#include "radix.h"
[Code] ....
My output:
sorted array is:
0 0 0 0 0 0 0 0 0 0
C++ :: Sort Data From Text File Into Array As Its Being Read?
Feb 12, 2013I am suppose to make a program that reads in data from a text file (integers only) and sorts them as it inserts them into an array of size 10. I did this using an insertion sort, which worked great. But now I am being told that I need the function has to read ALL of the numbers in the text file, not just the first 10, and I am not allowed to store them THEN sort, it has to be sorted as being stored.
This is what I have for sorting first 10
void sortArray(int iArray[])
{
string fileName = "";
fstream inFile;
int tmp = 0;
[Code]....
Visual C++ :: Employee Payroll - Read Data From Text File And Sort
Nov 11, 2013i tring to write a employee payroll code with functions and read data from the txt. file and also bubble sort that sorts and displays starting from employees last name and calculations.
//txt file//
Hours Pay rate empID first name last name
40.0 10.00 A1234 Jane Adams
50.0 10.00 L8765 Mary Lincoln
25.5 10.85 W7654 Martha Washington
52.0 15.75 A9876 John Adams
45.0 25.00 W1235 George Washington
40.25 55.00 L9087 Abraham Lincoln
30.0 9.75 T9876 William Tell
42.5 12.50 M7654 Missy Muffett
30.0 10.00 P8765 Peter Piper
and here is my code
Code:
#include <iostream>
#include <cstdio>
#include <fstream>
#include <string>
#include <iomanip>
using namespace std;
const int SZ = 55;
void tellUser();
[Code] .....
here are the errors the are giving
Code:
payroll.cpp: In function "int bubbleSort()":
payroll.cpp:52:8: error: "lastpos" was not declared in this scope
payroll.cpp:52:18: error: "numemp" was not declared in this scope
payroll.cpp:56:10: error: "swapmade" was not declared in this scope
payroll.cpp:57:16: error: "i" was not declared in this scope
[Code] ....
C++ :: How To Sort A 1D Array Using Function Sort
Mar 22, 2013how to sort a 1D array using function sort().but if i have a 2D array how do i sort only 1 row of it (or column)?
View 2 Replies View RelatedC/C++ :: Bubble Sort And Selection Sort?
Feb 19, 2014You will write a program that uses a multidimensional array having 3 rows and 8 columns and sorts each of the rows using both a bubble sort and a selection sort.
You must declare the array inside of main. You will have a for loop containing the calls to bubbleSort and selectionSort. You need to pass into function bubbleSort and selectionSort the following: 1) each column of the multidimensional array, 2) the size of the column, and 3) a particular row number of the multidimensional array to be used for printing out the "pass" shown on the following pages.
I keep getting an error that the identifier for bubbleSort and selectionSort is not found. (Error C3861) Also, I feel like I'm missing something in int main() to get it to sort properly.
# include <iostream>
using namespace std;
int main()
{
[Code].....
C++ :: How To Sum Row And Column Of 2D Arrays
Apr 11, 2013For example If I have the following . How would I sum each row and column ??
For example
1 2 3 4 5
0 1 3 8 9
C++ :: Iterating Over Either Row Or Column?
Jul 3, 2014Suppose I want to represent an apartment building in terms of floors and rooms with a single data object. Each floor has the same number of rooms at any given time. During the course of the program, I will need to change the number of floors occasionally and will need to change the number of rooms on each floor occasionally. (Don't worry about the building permits needed to do this.) Now, I also want to be able to iterate over either each floor (think "row") or each room (think "column"). For example, I might want to program the equivalent of "Johnson, go fix all the front doors on the 8th floor" or the equivalent of "Johnson, go fix all the front doors to room B on each floor". (Yeah, I know, for the latter I could iterate over each floor and then access room B but that doesn't feel as "clean" as being able to iterate over a separate room/column.)
View 7 Replies View RelatedC++ :: Row And Column Index?
Dec 16, 2013If 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;
}
C/C++ :: Iterating Over Either Row Or Column?
Jul 31, 2014Suppose I want to represent an apartment building in terms of floors and rooms with a single data object. Each floor has the same number of rooms at any given time. During the course of the program, I will need to change the number of floors occasionally and will need to change the number of rooms on each floor occasionally. (Don't worry about the building permits needed to do this.)
Now, I also want to be able to iterate over either each floor (think "row") or each room (think "column"). For example, I might want to program the equivalent of "Johnson, go fix all the front doors on the 8th floor" or the equivalent of "Johnson, go fix all the front doors to room B on each floor". (Yeah, I know, for the latter I could iterate over each floor and then access room B but that doesn't feel as "clean" as being able to iterate over a separate room/column.)
