Comparing two vectors sequential order

[aggsyb]

I have two vectors

std::vector<int> numberSet1, numberSet2;

numberSet1 contains 21,24

numberSet2 contains 20, 22, 23, 25 , 26 , 27

Is there anyway to determine if numberSet1 can sequentially fit into numberSet2 ?

Combined the numbers can go up at a count of 1? 20,21,22,23,24,25,26,27 I just want some kind of "return" to say , "numberSet1 fits the sequence"

[Gkneeus]

show us your code. So we can know how to deal with it, you don't want someone elses complicated code you can't understand.

[aggsyb]

I dont have any code, as I said I have 2 vectors , numberSet2 is sorted by size. I do not know how to check if a vector can fit into the sequencing of another vector. So infact yes I would like to look at somebody else's code, complicated or not. That will at least give me the opportunity to break down whats happening and learn something new while accomplishing a task of mine.

[Cubbi]

Correct me if I misunderstand you ("fit sequentially" is not a well-known term), but you're asking whether two sorted sequences, such as {21,24} and {20,22,23,25,26,27} form a continuous integer range when merged?

You could use std::merge to do the merge, and then compare it for equality with the range of the same size and starting value:

#include <vector>
#include <iostream>
#include <algorithm>
#include <numeric>

int main()
{
    std::vector<int> numberSet1 = {21,24};
    std::vector<int> numberSet2 = {20, 22, 23, 25 , 26 , 27};

    std::vector<int> merged;
    std::merge(numberSet1.begin(), numberSet1.end(),
               numberSet2.begin(), numberSet2.end(),
               back_inserter(merged));

    std::vector<int> range = merged;
    std::iota(range.begin(), range.end(), range.front());

    if(merged == range)
        std::cout << "The merged vectors form a continuos integer range\n";
    else
        std::cout << "The merged vectors do NOT form a continuos range\n";
}

(if you like boost, you can avoid constructing the second vector and just compare to a numeric range)

[keskiverto]

Boost, or a functor that has state.

There is also std::set_union that differs from std::merge a tiny bit: if same value occurs in both sets, then result.size() < set1.size() + set2.size()

Both algorithms require sorted input. The OP test will fail if either input set contains duplicate values.

Also note that on success, result.front() + result.size() == result.back() + 1.

std::adjacent_difference does potential stuff too.


"Is there any way"? Yes, many ways. If you know your input well, then you might avoid some brute force.