Sort arrays by elements

Question

I have three String arrays

A: [-22, -3, 2.2, a]
B: [-22, -3, 2.2, b]
C: [-22, 0, 2.2]

After sorting I want to get this sequence

C: [-22, 0, 2.2]
A: [-22, -3, 2.2, a]
B: [-22, -3, 2.2, b]

The comparison between a pair of arrays is done on the first element in the arrays. If the element is identical, the second element, and so on.

What comparator must be used?

to khelwood string array; to WasiAhmad i get first value from A (-22) after i get first value form B (-22), if they are equal -> compare second value from A (-3) with second value from B(-3) and etc. — dmitry_dreko, Feb 02 '17 at 15:26
Amazingly, there is no built-in comparator or function in the Java API to sequentially compare arrays, streams, or iterables. But you can easily write your own. — Patrick Parker, Feb 02 '17 at 15:38
@dmitry_dreko first you need to explain why C is being sorted before A. — Patrick Parker, Feb 02 '17 at 15:56
@PatrickParker because second value in C more than second value in A — dmitry_dreko, Feb 02 '17 at 16:06
you can use radix sort for comparing each array with another , and for comparing in array you can convert all elements to String and the use the Array.sort() method , but i'm curious to know why are you doing this ? — Mohsen_Fatemi, Feb 02 '17 at 16:10
@dmitry_dreko you said " because second value in C more than second value in A " which means you want a Descending sort. However, since you have sorted A before B you obviously want an Ascending sort. Which is it!? — Patrick Parker, Feb 02 '17 at 16:25

score 0 · Answer 1 · answered Feb 02 '17 at 16:30

#include <string>
#include <vector>
#include <iostream>
#include <algorithm>

using namespace std;

struct values{
    vector<string> ve;
}array[100];

bool comp(values a, values b){
    if(a.ve.size()<b.ve.size() || a.ve<b.ve)
        return true;
    return false;
}

int main(){

    int number, size;
    string str;
    cin>>number; //Number of string arrays
    for(int i=0;i<number;i++){
        cin>>size; // Number of element in each array
        for(int j= 0;j<size;j++){
            cin>>str;
            array[i].ve.push_back(str);
        }

    }
    sort(array, array+number, comp);

    for(int i=0;i<number;i++){
        for(int j= 0;j<array[i].ve.size();j++){
            cout<<array[i].ve[j]<<" ";
        }
        cout<<"\n";

    }
    return 0;
}

Input:

3      
4
-22 -3 2.2 a
4
-22 -3 2.2 b
3
-22 0 2.2

Output:

-22 0 2.2 
-22 -3 2.2 a 
-22 -3 2.2 b

why have you answered a java question with c++ code? – Patrick Parker Feb 02 '17 at 16:47 — Patrick Parker, Feb 02 '17 at 16:47
Ooops i didn't notice java tag. – Masum Feb 02 '17 at 16:54 — Masum, Feb 02 '17 at 16:54

Sort arrays by elements

1 Answers1