Mapping Vectors

Is there a good way to map vectors? Here's an example of what I mean:

vec0 = [0,0,0,0,0,0,0,0,0,0,0]
vec1 = [1,4,2,7,3,2]
vec2 = [0,0,0,0,0,0,0,0,0]
vec2 = [7,2,7,9,9,6,1,0,4]
vec4 = [0,0,0,0,0,0]

mainvec =
[0,0,0,0,0,0,0,0,0,0,0,1,4,2,7,3,2,0,0,0,0,0,0,0,0,0,7,2,7,9,9,6,1,0,4,0,0,0,0,0,0]

Lets say mainvec doesn't exist (I'm just showing it to you so you can see the general data structure in mind.

Now say I want mainvec(12) which would be 4. Is there a good way to map the call of these vectors without just stitching them together into a mainvec? I realize I could make a bunch of if statements that test the index of mainvec and I can then offset each call depending on where the call is within one of the vectors, so for instance:

mainvec(12) = vec1(1)

which I cou开发者_高级运维ld do by:

mainvec(index)
if (index >=13)
    vect1(index-11);

I wonder if there's a concise way of doing this without if statements. Any Ideas?

Are you looking for something like this?

using System.Collections.Generic;
namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] vec0 = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
            int[] vec1 = { 1, 4, 2, 7, 3, 2 };
            int[] vec2 = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
            int[] vec3 = { 7, 2, 7, 9, 9, 6, 1, 0, 4 };
            int[] vec4 = { 0, 0, 0, 0, 0, 0 };
            List<int> temp = new List<int>();
            temp.AddRange(vec0);
            temp.AddRange(vec1);
            temp.AddRange(vec2);
            temp.AddRange(vec3);
            temp.AddRange(vec4);
            int[] mainvec = temp.ToArray();
        }
    }
}

I would create a class that would receive array of lengths, and have a method to give you Array number and Index inside the array for a given index in the combined list.

It would be wrapped by a class that will get references to the actual arrays and an indexer to bring you to the right element.

It looks like your doing basic list concatenation, in which case the Concat function would seem to be the most straight forward way of doing things. In real-live code terms, somethng like:

var vec0 = new[] {0,0,0,0,0,0,0,0,0,0,0};
var vec1 = new[] {1,4,2,7,3,2};
var vec2 = new[] {0,0,0,0,0,0,0,0,0}; 
var vec3 = new[] {7,2,7,9,9,6,1,0,4};
var vec4 = new[] { 0, 0, 0, 0, 0, 0 };

var mainvec = vec0.Concat(vec1).Concat(vec2).Concat(vec3).Concat(vec4).ToList();
mainvec[12] == 1;

I'm not really sure of the context behind what you are wanting to do, so there may be a more direct way of doing things, but based on what you've got, this seems the simplest to me.

I would use a jagged array.

You still have to have a loop, but you can keep the separate vectors without redundancy:

var mainvec = new int[][]{vec0, vec1, vec2, vec3, vec4};

int desiredInd = 12, totalInd = 0, rowInd = 0, result;

while(rowInd < mainvec.Length && (totalInd + mainvec[rowInd].Length) <= desiredInd)
{ 
    totalInd += mainvec[rowInd++].Length;
}

if(rowInd < mainvec.Length && (desiredInd - totalInd) < mainvec[rowInd].Length)
{
  result = mainvec[rowInd][desiredInd - totalInd];
}