Using For Loop to Add Numbers to a Vector

问题

I want to add numbers 1 through 10 to an empty vector using a for loop. So I know that it should look like this:

for (int i = 1; i <=10 ; i++){

//some code that adds 1 - 10 to a vector

}

After the code has ran, I should get a vector that looks like this: {1,2,3,4,5,6,7,8,9,10}.

Can someone help me please?

回答1:

const int N = 10;

std::vector<int> v;
v.reserve( N );

for ( int i = 1; i <= N; i++ ) v.push_back( i );

Or

const int N = 10;

std::vector<int> v( N );

int i = 1;
for ( int &x : v ) x = i++;

Or

#include <numeric>

//...

const int N = 10;

std::vector<int> v( N );

std::iota( v.begin(), v.end(), 1 );

Or

#include <algorithm>

//...

const int N = 10;

std::vector<int> v( N );

int i = 1;
std::for_each( v.begin(), v.end(), [&i]( int &x ) { x = i++; } );

Or

#include <algorithm>
#include <iterator>

//...

const int N = 10;

std::vector<int> v;
v.reserve( N );

int i = 1;
std::generate_n( std::back_inserter( v ), N, [&i] { return i++; } );

All these methods use for loop

回答2:

You can do this by simply pushing value in the vector.. as the vector has a property of push_back to add value in it.

#include <iostream>
#include <vector>

int main ()
{
  std::vector<int> myvector;

  for(int i=1 ; i<=10 ;i++)
     myvector.push_back(i);

  return 0;
}

the vector will then contain : {1,2,3,4,5,6,7,8,9,10}

For more You can read this references: http://www.cplusplus.com/reference/vector/vector/push_back/

来源：https://stackoverflow.com/questions/27847128/using-for-loop-to-add-numbers-to-a-vector