C++ Program to Merge Two Sorted Vectors

This C++ Program which combines two sorted arrays. The program uses two user-defined functions enter_elem( ) and comb( ). The function enter_elem( ) takes number of elements of the vector as the input and runs a for loop to push elements into the vector. The vectors are then sorted and passed into the function comb( ) which returns a combined vector. The elements of the combined vector are then output to the standard output stream.

Here is source code of the C++ program which combines two sorted arrays. The C++ program is successfully compiled and run on a Linux system. The program output is also shown below.

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/*
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 * C++ Program to Combine two Sorted Arrays

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 */
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#include<iostream>
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#include<vector>
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#include<algorithm>
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using namespace std;
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/* Function to input vector elements */
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void enter_elem(vector<int>& a)
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{
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    int alen, val;
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    cout << "Enter number of elements : ";

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    cin >> alen;
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    for (int i = 0; i < alen; i++)
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    {
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        cin >> val;
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        a.push_back(val);
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    }
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}
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/* Function to combine two integer vectors */

vector<int> comb(vector<int> a, vector<int> b)

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{
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    int alen = a.size();
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    int blen = b.size();
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    int tlen = alen + blen;
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    vector<int> c(tlen);
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    int i = 0, j = 0, k = 0;
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    while (i < alen && j < blen)
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    {
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        if (a[i] < b[j])
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            c[k++] = a[i++];
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        else
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            c[k++] = b[j++];
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    }
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    while (i < alen)
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        c[k++] = a[i++];
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    while (j < blen)
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        c[k++] = b[j++];
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    return c;
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}
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int main()
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{ 
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    vector<int> a;
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    vector<int> b;
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    cout << "Initialising vector A" << endl;

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    enter_elem(a);
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    sort(a.begin(), a.end());
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    cout << "Initialising vector B" << endl;

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    enter_elem(b);
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    sort(b.begin(), b.end());
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    vector<int> c = comb(a, b);
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    for (int i = 0; i < c.size(); i++)
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        cout << c[i] << "  ";
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    cout << endl;
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}
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$ g++ main.cpp
$ ./a.out
Initialising vector A
Enter number of elements : 5
3 1 5 3 7
Initialising vector B
Enter number of elements : 3
8 5 10
1  3  3  5  5 7  8  10