c++ - vector 下标超出范围错误 C++

Question

#include <iostream>  
#include <vector>  
#include <iomanip>  
#include <cstdlib> 
#include <algorithm> 

using namespace std;  


void determine_grade (double &, char & );  
double calc_average (vector <double> averagevector);  
double find_highest (vector <double> highestvector);  
double find_lowest (vector <double> lowestvector);  




int main ()  
{  
double average = 0.00;  
double highest = 0.00;  
double lowest = 0.00;  
double input;   
char letter;
double score = 0;
vector <double> vecinput(0);  

for (int i = 0; i < vecinput.size(); i++)  
 {  
  cout << " Enter result " << vecinput[i] << "(or -1 if no more result):";
  cin >> input;  
  vecinput[i] = input; 
  if (input < 0 || input > 100) 
  {
      cout << " Invalid Input";
  }
  else(input == -1);
  {
      break;
  }


}

determine_grade(score, letter);

cout << " Summary of the Results:" << endl;  
cout << " Result" << vecinput.size()<<   
cout << setprecision(2) << fixed << score << "Grade" << letter << "\n";

average = calc_average(vecinput);  
cout << " The average of the results =" << setprecision (2) << fixed  << average <<       "\n";  


lowest = find_lowest(vecinput);  
cout << " The lowest of the results =" << setprecision (2)<< fixed << lowest << "\n";  


highest = find_highest(vecinput);  
cout << " The highest of the results =" << setprecision (2) << fixed << highest << "\n";  


system ("Pause");  
return 0;  
}



double calc_average(vector <double> averagevector) // This function will find the  average off the results.  
{  
double total = 0.00;  
double average = 0.00;  
for (int i = 0; i < averagevector.size(); ++i)  
{  
    total += averagevector[i];  
}  
average = (double) total / averagevector.size();   
return average;  
  }  


  double find_highest (vector <double> highestvector) // This function will find the  higest grade of the results.  
{  
double max= 0.00;  
max = *max_element(highestvector.begin(),highestvector.end());

 return max;
}  
double find_lowest (vector <double> lowestvector) // This function will find the lowest     grade of the results.  
{  
 double min = 0.00;
min = *min_element(lowestvector.begin(),lowestvector.end());

 return min;
}  


void determine_grade (double &num, char &grade)  
{  

if (num >= 90 && num <= 100)  
    grade = 'A';  
    else if (num >= 70 && num <= 89)  
    grade = 'B';  
    else if (num >= 60 && num <= 69 )  
    grade = 'C';  
    else if (num >= 50 && num <= 59)  
    grade = 'P';  
    else   
    grade = 'U';  



    } 

我正在尝试编写一个必须显示最高、最低等级的程序。我还必须显示平均值和字母等级。我收到一个 vector 下标超出范围的错误。每当我尝试运行该程序时，都在第 932 行。我不确定我做错了什么。

现在我得到一个错误， vector 迭代器不可微分

Answer 1

i <= vecinput.size()

.size()返回 vector 的大小，它们的索引是从零开始的，所以你要越过 vector 的末尾。

使用 <而不是 <= .

还要学习如何使用调试器，因为您可以使用调试器准确找出错误发生的位置。