C++ :: Why To Use Radix Sort
Apr 10, 2013why we use radix sort.
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C :: 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 :: Space Complexity Of Radix Sort?
Sep 2, 2013I was just going through Radix Sort algorithm. Though I got the logic and the concept used in it, I am still pretty much confused about the space complexity being O(k+n) for this algorithm. (where, k is the max no of digits in a number, and n is the no. of inputs to be sorted).
View 1 Replies View RelatedC++ :: Radix Sort Not Working - Implementation Using Two Tables
Jun 13, 2014I'm trying ultimately to do a radix sort. I'm going with the implementation using two tables. One will initially hold the unsorted values then hold the partially sorted values thereafter. The other will be an array of linked lists which will be where the radix sort is done. Here is my code thus far:
Main
#include <iostream>
#include <fstream>
#include "radix.h"
#include "radix.cpp"
using namespace std ;
int main ( int argc , char * argv [ ] ) {
ifstream input ( argv [ 1 ] ) ;
[Code] ....
It appears to be crashing during void insert_into_sorted ( int to_insert , int place ) ; and I'm not sure why.
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++ :: 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 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 Use Bubble Sort
Feb 20, 2012how can i use my function now in the main ... after i put the numbers for example i want them to be sorted in ascending or descending order
PHP Code:
# include <iostream>
using namespace std;
int main () {
int array [10];
cout << " enter numbers : ";
for ( int i=0; i<10; i++)
[code]....
C :: How To Sort Strings As Alphabetical
Nov 25, 2014I'm trying to sort strings as alphabetical but somewhere i have error.
Code:
#include <stdio.h>
#include <string.h>
int main(){
char s[100][20];
int num;
char temp[20];
int i,j;
[Code]....
C :: How To Sort Array To Nth Term
Nov 7, 2014I know how to sort an array but how I can sort an array regard to nth term.
Example: 2 --> nth digit 4 45 62 1 900 105 -->inputs
Output: 001 004 105 900 045 065
C :: How To Sort Out And Drop Lowest Int
Feb 27, 2013IM SO CLOSE to finishing this program, how to sort out and drop the lowest int, between 8 ints. Is there any way I can do this? I have these ints:
grade1, grade2, grade3, grade4, grade5, grade6, grade7, grade8
My program already assigns them values. How can I find the lowest value and drop it?I literally do not know where to start, and this is the last thing I need *.*
C :: How To Make A Sort Function
Feb 28, 2013Im suppose to make a "poor mans" variation to the Sort function built into unix. The program is suppose to read in a file and sort the contents of the file. So its a variation of the Unix Sort feature. I have remade the readLine function we were provided so that it doesnt use fgets. where to go from here, Not sure on how to make a sort function. Here are the reqirements of the program:
Code:
• Re-implement the readLine() function so that it no longer makes use of fgets(). Instead,
process the input on a given line character-by-character.
• Provide code which will create a data structure similar to argv to hold all of the words to be sorted. Use malloc() to ensure that each entry has just the required number of bytes needed to store the words. The final entry in your array should be the NULL pointer.
• Implement a sort() function which will rearrange the words in sorted order. To swap two words in your array, note that only a pair of pointers need to move. The strings themselves, once established, will never move. Heres what i have:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_LINES 1000 /* maximum number of reminders */
#define WORD_LENGTH 10 /* max length of reminder message */
[code]....
C :: Merge Sort Algorithm
Dec 24, 2014 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]...
C :: Subarrays For Merge Sort
May 15, 2013Code:
/* 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 ?
C :: Multiplication With Sort Function
Oct 30, 2014I need to include validation to only accept numbers and to only the last four odd numbers in the table.
Code:
#include <stdio.h>void main() {
int upper, range, i;
printf("Enter an integer to find multiplication table: ");
scanf("%d",&upper);
[Code].....
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 ?
View 1 Replies View RelatedC++ :: Using STL Sort With Custom Classes?
Oct 8, 2013I've written a doubly linked list per my assignment instructions. I've implemented begin() and end() iterators for it, and they work with no problems when traversing the list. However, I need to sort the elements in the list. We are allowed to use the sort function defined in the <algorithm> header since we haven't yet covered sorting algorithms.
But, I'm running into a ton of problems. I figured as long as the begin() and end() iterators were defined for the list, then sort(list.begin(), list.end(), compare) would do the trick. The main errors I'm getting are:
error: no type named iterator_category
error: no type named value_type
error: no type named difference_type
error: no type named pointer
error: no type named reference
And also errors for no match of the + and - operators for the iterator class.
I understand reference, pointer, and value_type, but I have no idea about iterator_category and difference_type. Additionally, I'm a little unsure why the + and - operators need to be overloaded.
C++ :: Can't Sort Node Based Upon Value
Apr 22, 2013I can't sort node based upon there value to sort nodes on the basis of the Nodes value in ascending order
if(Current_Node->get_value() < Last_Current_Node->get_value())
{
temp = Current_Node->get_next();
Current_Node->set_next(Last_Current_Node);
Last_Current_Node->set_next(temp);}
C++ :: How To Optimize Bubble Sort
Mar 24, 2013How to optimize this bubble sort program?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <time.h>
#include <cstdlib>
#include <iostream>
#include <ctime>
using namespace std;
int main() {
long *A;
A = new long[100000000];
[Code]] .....
C++ :: How To Sort Integer Array
Jul 28, 2013I want to sort an array like Myarray[3][4] based on the second column while other correspondent rows exchange consequently.
My array is as follows:
3 8 7 2
9 12 0 4
12 2 14 1
I want to sort it based on the second column using “std::qsort" or "std::sort” or other quick method that would lead to the following :
12 2 14 1
3 8 7 2
9 12 0 4
C++ :: Sort Payroll Structures?
Apr 28, 2014how these structures and arrays work which is why although I added alot more code than given, I sent it into my teacher and he was puzzled with my project. So I brought it back to a payroll calculator unsorted.
Sort the payroll data, and output the data to the file in order by gross pay (lowest to highest)
#include <fstream>
#include <iostream>
#include <cstdlib>
[Code]....
C++ :: How To Sort Arrays Alphabetically
Feb 25, 2014I need to sort the array alphabetically but I really do not how. I tried to do it below but it didn't work.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
void sort(ifstream& infile){
int number;
infile>>number;
[Code]...
C++ :: Linked List Sort By Age
Mar 22, 2013I know how to add a node and delete a node from the beginning and from the end of the List. Now I want to sort the List by Age. I tried everything but there must be a very little mistake that I can't find. Here is my code:
#include <iostream>
using namespace std;
struct Node {
char name[20];
int age;
double height;
[Code] ....
C/C++ :: How To Sort Through Large List
Aug 12, 2014What I want to create is a program that sorts through a huge list (millions of lines).
I want it to get rid of any line that contains a word that isn't in an English dictionary.
Example list:
00sdfdsf
ahdadsg
angel
ksjflsjdf
green
green000
carrot
and it would go through millions like that, giving me only:
angel
green
carrot
as my new list.
How could I go about this? What extra programs would I need?
C++ :: Merge Sort For Large N
Apr 8, 2013My 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]....