如何从控制台读取分隔的数字?

I'm trying to do a simple task of reading space separated numbers from console into a vector<int>, but I'm not getting how to do this properly.

我尝试做一个简单的任务，从控制台读取分隔的数字到向量，但是我不知道如何正确地做这个。

This is what I have done till now:

这就是我现在所做的:

int n = 0;
vector<int> steps;
while(cin>>n)
{
    steps.push_back(n);
}

However, this requires the user to press an invalid character (such as a) to break the while loop. I don't want it.

但是，这需要用户按一个无效字符(如a)来中断while循环。我不想要它。

As soon as user enters numbers like 0 2 3 4 5 and presses Enter I want the loop to be broken. I tried using istream_iterator and cin.getline also, but I couldn't get it working.

一旦用户输入诸如0 2 3 4 5之类的数字并按Enter，我希望循环被破坏。我尝试使用istream_iterator和cin。getline也是，但是我不能让它工作。

I don't know how many elements user will enter, hence I'm using vector.

我不知道用户会输入多少元素，因此我使用向量。

Please suggest the correct way to do this.

请建议正确的做法。

5 个解决方案

#1

Use a getline combined with an istringstream to extract the numbers.

使用一个getline和一个istringstream来提取数据。

std::string input;
getline(cin, input);
std::istringstream iss(input);
int temp;
while(iss >> temp)
{
   yourvector.push_back(temp);
}

#2

To elaborate on jonsca's answer, here is one possibility, assuming that the user faithfully enters valid integers:

要详细说明jonsca的答案，这里有一种可能性，假设用户忠实地输入有效整数:

string input;
getline(cin, input);

istringstream parser(input);
vector<int> numbers;

numbers.insert(numbers.begin(),
               istream_iterator<int>(parser), istream_iterator<int>());

This will correctly read and parse a valid line of integers from cin. Note that this is using the free function getline, which works with std::strings, and not istream::getline, which works with C-style strings.

这将正确读取和解析cin中的有效整数行。注意，这里使用的是免费函数getline，它与std::string一起工作，而不是与c风格的字符串一起工作的istream::getline。

#3

This code should help you out, it reads a line to a string and then iterates over it getting out all numbers.

这段代码应该可以帮助您，它将一行读入一个字符串，然后迭代它得到所有的数字。

#include <iostream>
#include <sstream>
#include <string>

int main() {
    std::string line;
    std::getline(std::cin, line);
    std::istringstream in(line, std::istringstream::in);
    int n;
    vector<int> v;
    while (in >> n) {
        v.push_back(n);
    }
    return 0;
}

#4

Also, might be helpful to know that you can stimulate an EOF - Press 'ctrl-z' (windows only, unix-like systems use ctrl-d) in the command line, after you have finished with your inputs. Should help you when you're testing little programs like this - without having to type in an invalid character.

同样，如果您知道您可以在完成输入后，在命令行中激发EOF - Press 'ctrl-z'(仅在windows中，类unix系统使用ctrl-d)，这可能会有所帮助。当你在测试像这样的小程序时应该会有所帮助——而不需要输入无效的字符。

#5

Prompt user after each number or take number count in advance and loop accordingly. Not a great idea but i saw this in many applications.

提示用户在每一个数字后或提前取数字计数，并相应循环。这不是个好主意，但我在很多应用中都看到了。

#1