std :: cout在for循环内不起作用 [英] std::cout not working inside a for-loop

问题描述

我是C ++的新手，现在我正在学习《 加速的C ++ 》一书。我完成了第三章（向量），然后开始了本练习：

I'm new to C++, and right now I'm learning from the book called Accelerated C++. I finished the third chapter (vectors), and I came to this exercise:

编写一个程序，计算每个单词在其输入中出现的次数。

"Write a program to count how many times each distinct word appears in its input."

经过一番思考，我开始研究它。我想测试该程序，但std :: cout无法正常工作。我把 cout<< test; 在我的代码中的几个地方查看问题出在哪里，结论是它在第一个for循环内不起作用。不建议我使用地图来解决问题，因为我正在研究矢量。变量不是英语的，所以我将翻译一些变量，让您了解发生了什么事情。

After some thinking, I started working on it. I wanted to test the program, but std::cout wasn't working. I put cout << "test"; on a few places in my code to see where's the problem, and the conclusion is that it doesn't work inside the first for-loop. Don't recommend me to use maps to solve the problem, because I'm working on vectors. The variables aren't in English, so I'll translate some for you to know what's going on:

recenica-句子； rijec-一个字； vel_vektora-向量的大小； duz_recenice-句子的长度； br_ponavljanja-单词在句子中出现的次数；

recenica - the sentence; rijec - a word; vel_vektora - size of the vector; duz_recenice - length of the sentence; br_ponavljanja - number of times a word appears in the sentence;

#include <vector>
#include <iostream>
#include <string>

using std::string;      using std::vector;
using std::cin;         using std::cout;
using std::endl;



int main()
{
    string rijec;
    vector<string> recenica;

    while (cin >> rijec) recenica.push_back(rijec);
    cout << endl;

    typedef vector<string>::size_type vel_vektora;
    vel_vektora duz_recenice = recenica.size();
    cout << "test0, ";

    for (int i = 0; i < duz_recenice - 1; ++i)            
    {   
        cout << "test, !";
        int br_ponavljanja = 1;

        for (int j = i + 1; j < duz_recenice; ++j)
        {
                cout << "test2, ";
                if (recenica[i] == recenica[j])
                {
                                cout << "test3, ";
                                ++br_ponavljanja;
                                recenica.erase(recenica.begin() + j);
                }     
                cout << "test4, ";
        }        
        cout << recenica[i] << ": " << br_ponavljanja << endl;        
    }
    cout << "test5, ";                
    getchar();
    return 0;        
}

std :: cout <有什么问题？

推荐答案

添加<< flush 刷新输出缓冲区（每个位置）。

Add << flush to flush your output buffer (each place).

或使用<< endl ，都添加换行符和刷新。

Or use << endl, which both adds newline and flushes.

代码存在问题，特别是对于空输入，但这就是你要解决的问题了解有关信息，所以我会留给您！ ：-）

There are problems with the code, especially for empty input, but that's what you're out to learn about, so I'll leave you to it! :-)

干杯hth。，

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