About Input

[lifeisamovie]

How can I read a sequence of ints from cin and store the values two vectors at the same time?like this, vector val1,val2; int i,j; while(cin>>i) val1.push_back(i); while(cin>>j) val2.push_back(j);

[pezy]

@lifeisamoive

Did you mean:

int i, j;
while ( cin >> i >> j ) {
    vec1.push_back(i);
    vec2.push_back(j);
}

:walking:

[lifeisamovie]

Not really,I want to read a sequence of ints into one vector completely after another.Just like this, 1 2 3 4 //vec1,一次输入1 2 3 4,到vec1 5 6 7 8//vec2,第二次输入5 6 7 8，到vec2, how can I do that?

all right,my English is not that good. Thanks a lot.

[pezy]

@lifeisamoive

这本来就是中文讨论区，直接说中文就好。

我明白你的意思了，但如何区分两次输入呢？每一次输入的数字个数固定（如 4）？还是弄个标记说明第一次输入完毕，如(#, -1 之类的特殊字符或数字)？

[lifeisamovie]

恩，我是想一次输入不确定长度的ints到一个vector，然后再输一串数字到另一个vector，你说的“弄个标记说明第一次输入完毕”挺好的

[pezy]

@lifeisamoive

没问题的，可以一行一行的来，一行就对应一个 vector，这也省了标记了。

#include <iostream>
using std::cout; using std::cin; using std::endl;
#include <string>
using std::string;
#include <vector>
using std::vector;
#include <sstream>

int main()
{ 
    vector<vector<int>> vecGroup(2);
    size_t index = 0;
    for (string line; std::getline(cin, line); ++index) {
        std::istringstream iss(line);
        for (int n; iss >> n; ) 
            vecGroup.at(index).push_back(n);
        if ( vecGroup.size() - 1 == index ) break;
    }

    // output
    for (size_t i = 0; i != vecGroup.size(); ++i) {
        cout << "vec" << i << ": ";
        for (auto n : vecGroup.at(i))
            cout << n << " ";
        cout << endl;
    }
}

测试如下：

// 输入：
1 2 3 4 5 6 7
8 9 10
// 输出：
vec0: 1 2 3 4 5 6 7
vec1: 8 9 10