C++ :: How To Scan Multiple Vectors For Common Elements Efficiently
Nov 6, 2013
we conform to the ISO C standard and this snippet of code : Code: vector<tree*> *leaves = new vector<tree*>[num_threads]; where num_threads is specified from command line arguments so not dynamically allocating it violates the standard.
Let's also assume num_threads is greater than one.
What I want to do is scan each vector in leaves for duplicates. If any two vectors in the set have matching addresses, they both immediately go onto the "unsafe" pile and will no longer be subject for testing.
If a vector clears one vector, we test it against the others in the set.
So if we have 3 vectors, A, B and C we test A against B then A against C. For efficiency, we then then just test B against C.
Like I said, I want a "safe" and "unsafe" pile. Every vector in "safe" is fully unique while every vector in "unsafe" is not unique.
I thought about just using a for-loop to loop through leaves and then iterate through each element but I'm not sure if that'll work just right out of the box.
View 14 Replies
ADVERTISEMENT
Mar 20, 2013
I have a dynamic number of lists coming in from a different method . i need to find out the common elements present in all of the lists .
How do i do it with intersect construct in C#.
Placing it in a loop gets me the elements common in the last comparison , but never gets me elements commong in all lists.
View 1 Replies
View Related
Mar 1, 2012
Say I have 5 vectors of unsigned char each of size 5. I want to take the max of each index and store it in a new vector. What is the most optimal way to accomplish this?
My slow code:
Code:
vector<unsigned char> vec1;
vector<unsigned char> vec2;
vector<unsigned char> vec3;
vector<unsigned char> vec4;
[Code]....
View 3 Replies
View Related
Mar 19, 2014
I create a list of vectors (a vector of n vectors of m elements).
std::vector <std::vector <int> > vsFA (n, std::vector<int>(n));
How I assign values? I try below, but not worked
void armazenaFA( std::vector <int> &vFA) // this function only knows about vFA
{ vsFA[n] [m]= simTime().dbl();
OR
vsFA[n].push_back(simTime().dbl());
}
View 1 Replies
View Related
Jan 23, 2015
So I'm trying to make two arrays, then the third array that will include common elements of those two arrays. I did make a code for that, but the problem is I don't know how to include that the elements do not repeat.
For example, if there are two arrays,
Elements of the first one: 2, 3
Elements of the second one: 2, 3, 2
The third array is going to be: 2 2
While I want it to be only 2.
#include <iostream>
using namespace std;
int* intersection(int* n1, int d1, int* n2, int d2, int& d3) {
d3=0;
for (int i=0; i<d1; i++) {
[Code] ....
View 14 Replies
View Related
Sep 19, 2014
How would I be able to let the user enter multiple heart rates which would all be separate.
Code:
printf("Enter your recorded Heart Rates ");
scanf("%d", &in_rate);
//formulas
if (gender == 'm'){
target = 226 - age;
} else if (gender == 'f'){
[Code]...
View 1 Replies
View Related
May 2, 2012
I am writing code to access vector elements as, to print first "n" elements of vectors out of its total N elements at a time.
For example, Total vector elements : N= 23
Want to print n elements at time : n =3
How this can be explored using vectors?
View 6 Replies
View Related
Apr 29, 2013
I'm trying to write a function that takes two linked lists and creates a third one with only the common elements.
It assumes the first list (the caller) has no dups, but it doesn't seem to be working. The program doesn't crash, it just hangs when it is supposed to display L3 (the third list)..everything else runs and is displayed fine.
template <typename T>
LList <T> LList <T>:: common (LList <T> &B)//common fct
{
Node <T> *hunter1 = Head;
[Code]......
View 10 Replies
View Related
Feb 9, 2014
I can't compile this code as I am at work and the computers are security protected, So i''l have to wait until i get home to test this, but I am pretty sure I am wrong. The problem is I have to create two vectors with 10 elements and input random numbers into it, then pick one of the elements of the second vector at random and append it to an element from the first vector at random. This has to be done 10 times and the I am assuming i have to print the 10 results. This is what I have:
#include <cstdlib>
#include <ctime>
#include <iostream>
using namespace std;
int main() {
vector<int> random (10);
[Code] ....
View 11 Replies
View Related
Feb 4, 2015
If I have a class object and multiple vectors, how do I make sure I store the same instance of that object in both vectors? For instance:
Object object;
std::vector<Object> vectorOne;
std::vector<Object> vectorTwo;
vectorOne.push_back(object);
vectorTwo.push_back(object);
Are the objects in both vectors the same instance of the object? Like if I called vectorOne[0].setValue(somethingDifferent); would the value be changed for the object in both vectorOne and vectorTwo? If not, how do I make sure that I only have one instance of the object I'm trying to store in multiple vectors?
View 15 Replies
View Related
Apr 13, 2014
I have a class 'A' which is almost perfect for my needs. Class 'B' uses class 'A' I've now designed Class 'C' and Class 'D' and noticed that there is a good chunk of code in class 'B', 'C' and 'D' for using Class 'A' is duplicated. I've separated out this code in specific, standalone functions in each of the classes. Now I'm wondering where this code should go. At the moment, the functions are duplicated in the three calling classes (B, C and D). Placing the functions into class 'A' would break the single responsibility principle. Inheritance to add functionality would likely break both SRP and LSP. The one that seems that it may work is composition.
However, Is designing a complete class just for a few functions over kill?
Would it be valid for classes 'B', 'C' and 'D' to access both the new class 'E' (which would depend on A) and the old class 'A' (which would have to be the same instance as the instance in the new class 'E'), or should the new class 'E' provide sufficient functionality so that Classes B, C and D don't need to access Class A directly? It would seem that its then an incomplete interface of the original object with additional functionality (ie, incompatible) Or should I do it a completely different way?
View 4 Replies
View Related
Sep 27, 2014
I used to use map to access elements. map has a good feature that it sort the element automatically. Now I need a map which can access element through multiple key values. So I choosed boost::multi_index_container. I defined a container as follows.
struct elem {
int a,b;
elem(int aa,int bb):a(aa),b(bb) {}
};
typedef multi_index_container <
[Code] ....
What I am wondering is whether boost::multi_index_container can sort elements automatically. Specifically, are all elements extracted through iterator from begin to end shown below having b values between 2 and 100?
test t;
test::iterator begin = t.lower_bound(make_tuple(1,2));
test::iterator end = t.upper_bound(make_tuple(1,100));
View 3 Replies
View Related
Jan 11, 2015
I have array of 100 elements and I'm trying to write elements which index is smaller than the index of the maximum element of the array. My problem is that I can't determine how big this array should be . I found which is my biggest index.
Code:
#include <visual_2013.h>
#include <stdio.h>
#include <stdlib.h>
#define DIM 10
void enterArray(int x[]);
void array2(int x[]);
int maxAndIndex(int x[], int n, int *index);
int main()
[Code]...
View 3 Replies
View Related
Jan 20, 2014
am trying to create a program that asks the user personal questions.
std::vector<std::string> name, age, favsinger;
std::cout << "Hello, what is your Name Age Favorite_Singer? ";
std::cin << name; //i want to store the user's info along with the sibling's
[Code]....
View 4 Replies
View Related
Apr 19, 2013
I have a txt file that looks like this:
Student ID:97707; Grades: 87.73, 90.41, 91.74, 95.04, 99.13; Name:Davis, Artur
Student ID:23628; Grades: 58.09, 65.18, 68.62, 68.62, 98.05; Name:Davis, Susan
Student ID:49024; Grades: 18.37, 66.06, 68.07, 80.91, 96.47; Name:DeGette, Diana
-I need to read the id, grades and names;
-The id to a separate array
-The grades to a 2-d array
-And the names to a c style string.
Where do I start, im having trouble read the dummy to start
int main() {
char filename[15] = "ex.txt";
string names[MAX_NAMES];
double grades[MAX_ROWS][MAX_COLS];
int id[MAX_IDS];
int index = 0;
ifstream fin;
[Code] .....
View 3 Replies
View Related
May 1, 2013
Write a C-program that efficiently multiplies a number by a factor 2 to the power n. The number to multiply and n are variables, which get a value at the start of the program.
Clue: 1 shift to the left is the same as multiplying by 2. 2 shifts to the left are the same as multiplying by 4. 3 shifts to the left are the same as multiplying by 8
View 7 Replies
View Related
Jul 9, 2014
I have accomplished this but it looks hacky if you ask me
time_t timeToNextFeed()
{
Leaf::Record* r = records->getRecord(0);
if (r != NULL)
[Code].....
View 2 Replies
View Related
Jun 27, 2014
have a problem with my code (I wish for answer with code). The conditions I have to grant:
- **Only** a pointer to an object must be saved in a **standard** class vector (e.g vector<ShapePtr>)
- Base class must be a polymorphic class (I call this class ShapePtr)
- I **must** have a deep copy process
- Constructor is **not** suppose to do a deep copy
- **clone()** is suppose to do the deep copy
Here is the code **provided** to me:
main.cpp
int main() {
typedef shared_ptr<Shape> ShapePtr;
vector<ShapePtr> shapevec;
[Code].....
View 1 Replies
View Related
Jun 30, 2014
Suppose your program has many concrete subtypes of Person, and each person will have their own file saved, with their type stored in that file. When reading the files to create the people again (of their proper types), what is the best method to maximize performance (and elegance by shortening the code)? Here is what I have so far.
First I used if statements, which is terrible, and now I've improved the performance logarithmically using std::map. I still suspect there is a better way, especially if there are going to be hundreds of different classes. If you want to test it, you can change the PATH constant to whatever path you want, or just leave it as an empty string, and the files will be created in the same directory as your cpp file. The part I'm trying to improve is pointed out in the comments.
struct Person {
std::string name;
Person (const std::string& newName) : name (newName) {}
virtual ~Person() = default;
};
struct Guy : Person {using Person::Person;};
struct Girl : Person {using Person::Person;};
[Code] ....
View 4 Replies
View Related
Sep 19, 2014
This is probably a very basic question, but I need to create two vectors and then loop through the vectors and output each pair that is found.
The user will input min1 and max1 with step1 for the first vector and min2 and max2 and step2 for the second vector. Then the loops will go through and return the combinations will return each pair of the two vectors.
So if I input min1=1 and max1=10 and step1=1 and same for vector two the return would be:
[1,1]
[1,2]
.
.
.
[10,10]
This is for part of a homework assignment, but I can't continue on the assignment without first getting this simple part to work.
View 1 Replies
View Related
Sep 17, 2014
i wrote the following code :
Code:
#include<stdio.h>#include<conio.h>
#include<stdlib.h>
int a[][4] = {15,9,10,25,6,2,4,7,32,19,42,8,21,17,18,0};
void boxes();
void display();
void main()
{int ch,r=3,c=3,t;
[Code]...
not able to esc when i press esc key.how to get rid of this.
View 4 Replies
View Related
Dec 13, 2014
I created a program that will create a file and print a list on it. Here is the code for my program:
Code:
int controlvalue(void) {FILE *controlvalue;
controlvalue = fopen("something.txt", "a+");
/* Series of fprintfs */
fclose (controlvalue);
return 1;}
Here is an example list created by my program:
Code:
[Gifts]Candy=45
Chocolate=32
Toy=128
Robot=754
Doll=1492
Star=21
Phone=72
Skateboard=87
Frame=314
Days=365
Perfume=421
I want to get the value of "Skateboard" on file. So I need to read 9 lines. On the 9th line, the gets() loop will stop. But, what if I only want to get the value of "Skateboard" as integer (87) and not a string? Also, is it possible to scan the value of Skateboard if it's located on a different (or unknown) line?
View 1 Replies
View Related
Jan 28, 2013
This is my code:
int main() {
int num;
printf("Please enter a number: ");
scanf("%d", num);
printf("%d", num);
return 0;
}
when i compile and run it, it stops working and doesn't printf the integer.
View 3 Replies
View Related
Dec 19, 2014
I'm writing a C++ module that is meant to recursively scan a directory and I'm curious what yall think of my strategy.
The program is a music player and so I'm trying to make the directory scanner as lightweight and efficient as I can. I've decided I want to scan the files in two passes- first I just want to get a list of all music files that are found in a directory/subdirectories and then I want to process the list and search for id3s/other tags.
As I'm a scanning the directory, I've decided to store the temporary list in a linked list where each node is containing an array of 100 strings. I did this because I obviously don't know how long the list will be and I from my understanding of the C++ vector class it basically just makes over sized arrays and moves them when it runs out of space. That sounded rather clunky to me, as did a traditional linked list.. I didn't see the point of allocating memory that many times in a row.
View 3 Replies
View Related
Mar 4, 2013
This is my text file.
bak kut teh[tab]888.0[tab]989.0
spicy chicken nugget[tab]999.0[tab]978.0
I'm experiencing some problem in trying to scan and put it into an array for the food names (e.g an array for food which consist of bak kut teh and spicy chicken nugget) and another 2 array for the other individual integer into C. However there seem to be some problem with my code.
Is there a difference if I use both tab and space instead of space for all?
Code:
#include<stdio.h>
int main() {
FILE *fp;
char food[100];
char buff[BUFSIZ];
float num;
[Code] ....
View 2 Replies
View Related
Dec 21, 2014
Is it possible to fgets() the string (or word) only after a delimiter? I yes then how?
Example: Code: printer, scanner, machine
Also, how can I sscanf() a string with an indefinite number of sizes and assign it to only one variable?
Example:
Code:
str = "I Love C programming 9000";
sscanf(str, "%s %d", strvar, intvar);
View 13 Replies
View Related
