对字符串C ++中的所有整数求和 [英] Sum all integers in a string C++

问题描述

我的代码中有一个C ++字符串，如下所示：

 1 2 3 4 5 6 7 8
  

我知道字符串是由空格字符分隔的整数组成的。

我是一个C ++新手，在Java中我只需要做：

  String str =1 2 3 4 5 6 7 8; 
 int sum = 0; 
 
 
 for（int i = 0; i  sum + = Integer.parse（str.split ）[i]; 
} 
  

对象在C ++？

有人建议我 stringstream 但我还是不能理解这个对象，

更新：有些人很好地试图帮助我，但仍然没有工作，也许是因为我的问题的一些怪癖，我以前没有澄清，所以这里：

  #include< iostream> 
 #include< string> 
 #include< sstream> 
 
 using namespace std ; 
 
 
 int main（）
 {
 freopen（variable-exercise.in，r，stdin）; 
 $ b b int sum = 0，start = 0; 
 string line; 
 
 
 while（getline（cin，line））{
 istringstream iss（line）; 
 
 while（iss>> start）{
 sum + = start; 
} 
 
 cout<<开始<< endl; 
 sum = start = 0; 
} 
 
 return 0; 
} 
  

Ah，输入文件包含以下内容：

  1 
 3 4 
 8 1 1 
 7 2 9 3 
 1 1 1 1 1 
 0 1 2 5 6 10 
  

因此，对于每一行，程序必须打印在字符串行中的所有整数。此示例将生成：

  1 
 7 
 10 
 21 
 5 
 24 
  

感谢

解决方案

有人建议我使用stringstream，但是我还是不能理解这个对象，我需要完全读取这个字符

我想你给了一个很好的建议。使用 std :: istringstream ，您可以只读在一个接一个的值，因为你会从标准输入（或任何其他输入流）中读取它们。

例如：

  #include< sstream& 
 #include< string> 
 #include< iostream> 
 
 int main（）
 {
 //假设在某些时候你有这个字符串... 
 std :: string s =1 2 3 4 5 6 7 8 9 10; 
 
 //你可以从中创建一个istringstream对象... 
 std :: istringstream iss（s）; 
 
 int i = 0; 
 int sum = 0; 
 
 //一个接一个读取所有值... 
 while（iss>> i）
 {
 // ...每次
 sum + = i时更新总和; 
} 
 
 std :: cout<<和; 
} 
  

I have a C++ string in my code that is like:

"1 2 3 4 5 6 7 8"

I know the string is composed of integers separated by a space char. How can I sum them?

I'm quite a C++ newbie and in Java I'd simply do:

String str = "1 2 3 4 5 6 7 8";
int sum = 0;


for (int i = 0; i < str.split(" ").length; i++ {
    sum += Integer.parse(str.split(" ")[i];
}

How can I do just like this with my string object in C++?

Some people suggested me stringstream but I still can't understand this object and I need to read the string entirely, getting every single digit within it.

Thanks in advance!

Update: some guys nicely tried to help me but still it's not working. Perhaps because of some quirk of my problem which I haven't clarified before. So here it goes:

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

using namespace std;


int main()
{
freopen("variable-exercise.in", "r", stdin);

int sum = 0, start = 0;
string line;


while(getline(cin ,line)) {
    istringstream iss(line);

    while(iss >> start) {
        sum += start;
    }

    cout << start << endl;
    sum = start = 0;
}

return 0;
}

Ah, the input file contains the following:

1
3 4
8 1 1
7 2 9 3
1 1 1 1 1
0 1 2 5 6 10

So, for each line, the program must print the sum of all integers in the string line. This example would generate:

1
7
10
21
5
24

thanks

解决方案

Some people suggested me stringstream but I still can't understand this object and I need to read the string entirely

I guess you were given a good advice. With std::istringstream you could just read in values one after the other as you would read them from the standard input (or any other input stream).

For instance:

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

int main()
{
    // Suppose at some time you have this string...
    std::string s = "1 2 3 4 5 6 7 8 9 10";

    // You can create an istringstream object from it...
    std::istringstream iss(s);

    int i = 0;
    int sum = 0;

    // And read all values one after the other...
    while (iss >> i)
    {
        // ...of course updating the sum each time
        sum += i;
    }

    std::cout << sum;
}

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