std::iota in C++

Store increasing sequence
Assigns to every element in the range [first, last] successive values of val, as if incremented with ++val after each element is written.

Template :

void iota (ForwardIterator first, ForwardIterator last, T val);

Parameters :

first, last
Forward iterators to the initial and final positions of the sequence
to be written. The range used is [first, last), which contains all the
elements between first and last, including the element pointed by
first but not the element pointed by last.

val
Initial value for the accumulator. 

Return Type :
None

// CPP program to illustrate
// std :: iota
#include <iostream> // std::cout
#include <numeric> // std::iota

// Driver code
int main()
{
    int numbers[10];
    // Initailising starting value as 100
    int st = 100;

    std::iota(numbers, numbers + 10, st);

    std::cout << "Elements are :";
    for (auto i : numbers)
        std::cout << ' ' << i;
    std::cout << '\n';

    return 0;
}

Output:

Elements are : 100 101 102 103 104 105 106 107 108 109

Application :
It can be used to generate a sequence of consecutive numbers.

// CPP program to generate
// a sequence of numbers using std :: iota
#include <iostream> // std::cout
#include <numeric> // std::iota

// Driver code
int main()
{
    int numbers[11];
    // Initailising starting value as 10
    int st = 10;

    std::iota(numbers, numbers + 11, st);

    std::cout << "Elements are :";
    for (auto i : numbers)
        std::cout << ' ' << i;
    std::cout << '\n';

    return 0;
}

OUTPUT :

Elements are : 10 11 12 13 14 15 16 17 18 19 20

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