Question

我有这段代码来平均文件中的分数。这是代码：

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <iomanip>

using namespace std;

ifstream fin("Quizzes.dat");
ofstream fout("readout2.dat");


int main(void)
{
  fout.setf(ios::showpoint);
  fout.setf(ios::fixed);
  fout.precision(2);
  int id, newid, count = 0;
  float score, maxscore, minscore, scoretotal = 0, testavg;
  fin >> id >> score;

  while (!fin.fail()) {
    maxscore = 0;
    minscore = 100;
    scoretotal = 0;
    count = 0;
    testavg = 0;
    newid = id;

    while (id == newid && !fin.fail()) {
      if (score <= minscore && score >= maxscore) {
        minscore = score;
        maxscore = score;
      }//end of if(score < minscore && score > maxscore)

      else if (minscore == maxscore && score == minscore) {
        scoretotal = scoretotal + score;
        count++;

      } else if (score <= minscore && minscore == maxscore) {
        minscore = score;
      }//end of else if(score < minscore && minscore == maxscore)

      else if (score >= maxscore && minscore == maxscore) {
        maxscore = score;
      }//End of else if(score > maxscore && minscore == maxscore)

      else if (score <= minscore) {
        scoretotal = minscore + scoretotal;
        count++;
        minscore = score;
      }//end of else if(score < minscore)

      else if (score >= maxscore) {
        scoretotal = maxscore + scoretotal;
        count++;
        maxscore = score;
      }//End of else if (score > maxscore)

      else {
        scoretotal = scoretotal + score;
        count++;
      }

      fin >> id >> score;
    }//end of while(id==newid)

    testavg = (scoretotal / count);
    fout << newid << setw(20) << testavg << endl;
  }//end of while(!fin.fail())
}

这是文件：

10234     67

10234    100

10234     53

10234     91

11245     89

11245     46

11245     99

14652    100

14652     56

14652     99

14652    100

14652     96

14652     78

19832     92

19832     78

19832     51

19832     76

19832     89

20014    100

20014    100

20014    100

20014    100

21140     43

21140     56

21140     90

21140     78

21140     63

21140     67

21140     89

22256     10

22256      7

22256      7

22256      2

22256     11

22256      2

22256      2

22256     13

22256      9

27654     83

27654     83

27654     83

27654     83

30021     78

30021     67

30021     92

30021     59

30021     82

30021     58

我遇到的问题是在文件的各个部分中，得分保持不变，并且不会添加任何内容。

Answer 1

尽量简化事情，你的程序很难阅读

#include <algorithm>
#include <iostream>
#include <map>
#include <vector>

int main()
{
  std::map<int, std::vector<int>> map;

  for (int id, score; std::cin >> id >> score;)
    map[id].push_back(score);

  for (auto const& id : map) {
    int total = std::accumulate(id.second.begin(), id.second.end(), 0); 
    std::cout << id.first << ": " 
      << total / static_cast<double>(id.second.size()) << '\n';
  }
}

如果您需要查找最低和最高分数，还可以使用min_element和max_element等算法。

Answer 2

我添加了一些诊断信息，因此您可以跟踪逻辑流程并找到问题所在。在我看来，你的7阶段if {} else {}结构过于复杂且逻辑上不正确。

#include <iostream>
#include <fstream>
#include <iomanip>

using namespace std;

ifstream fin("input.txt");
ostream& fout = cout;




int main (void)
{

fout.setf(ios::showpoint);
fout.setf(ios::fixed);
fout.precision (2); 
int id, newid, count=0;
float score, maxscore, minscore, scoretotal=0, testavg;


fin >> id >> score;

while(!fin.fail())
{
    maxscore = 0;
    minscore = 100;
    scoretotal = 0;
    count=0;
    testavg=0;
    newid=id;
    while(id==newid && !fin.fail())
    {
        if(score <= minscore && score >= maxscore)
        {
            cout << "1" << endl;
            minscore = score;
            maxscore = score;
        }//end of if(score < minscore && score > maxscore)
        else if (minscore == maxscore && score == minscore)
        {
            cout << "2" << endl;
            scoretotal = scoretotal + score;
            count++;
        }
        else if(score <= minscore && minscore == maxscore)
        {
            cout << "3" << endl;
            minscore = score;
        }//end of else if(score < minscore && minscore == maxscore)
        else if(score >= maxscore && minscore == maxscore)
        {
            cout << "4" << endl;
            maxscore = score;
        }//End of else if(score > maxscore && minscore == maxscore)

        else if(score <= minscore)
        {
            cout << "5" << endl;
            scoretotal = minscore + scoretotal;
            count++;
            minscore = score;
        }//end of else if(score < minscore)
        else if (score >= maxscore)
        {
            cout << "6" << endl;
            scoretotal = maxscore + scoretotal;
            count++;
            maxscore=score;
        }//End of else if (score > maxscore) 
        else 
        {
            cout << "7" << endl;
            scoretotal = scoretotal + score;
            count++; 
        }
        fin >> id >> score;
    }//end of while(id==newid)
    testavg = (scoretotal/count);
    fout << newid << setw(20) << testavg << endl;
}//end of while(!fin.fail())


}//End of int main(void)

代码没有拿起两个部分

2 个答案: