Question

我在标记的“Median”功能中遇到了一些麻烦。我收到一个错误，表示数组下标的'Horse [10] [double]'。我不知道如何解决这个问题，我正在寻求一些友好的帮助。

#include <cstdlib>
#include <iostream>
#include <math.h>

/*
Name: Horses2
Author: Grant Birkinbine
Date: 03/12/14 18:25
Description: A program that modifies the Horses program
*/

//Start

using namespace std;

//Class

class Horse{
  private:
          string name ;
          int lane;
          double time;

  public:

          Horse(string hname , int hlane , double htime){
                       name = hname ;
                       lane = hlane ;
                       time = htime;
                       }
          Horse(){
                  name = "" ;
                  lane = 0 ;
                  time = 0 ;
                  }

          void setname(string hname){
               name = hname;
               }
          void setlane(int hlane){
               lane = hlane;
               }
          void settime(double htime){
               time = htime;
               }

          string getname (){
                 return name ;
                 }
          int getlane(){
                 return lane;
                 }
          double gettime(){
                 return time;
                 }

          void print(){
               cout << "Horse Name: " << name << endl;
               cout << "Horse Lane: " << lane << endl;
               cout << "Horse Time: " << time << endl;
               cout << endl;  
               }     
};

//Main

void insertion_sort(Horse x[],int length);

int main(int argc, char *argv[])
{
cout << "Horse Race Results: " << endl << endl;
Horse ahorse[10];

ahorse[0] = Horse("American idol " , 1 , 45.41);
ahorse[1] = Horse("Bababooey " , 2 , 42.42);
ahorse[2] = Horse("Charlie Horse " , 3 , 40.94);
ahorse[3] = Horse("Dog Biscuit " , 4 , 43.55);
ahorse[4] = Horse("Echo " , 5 , 41.41);
ahorse[5] = Horse("Firefox " , 6 , 42.58);
ahorse[6] = Horse("Google " , 7 , 42.58);
ahorse[7] = Horse("Hoof-Hearted " , 8 , 44.57);
ahorse[8] = Horse("Ima Loozer " , 9 , 41.57);
ahorse[9] = Horse("Just Walking " , 10 , 50.00); 

//Sorting

int length = 10;
insertion_sort(ahorse, length);

double avg;
double x;
double max;
double min; 
avg=0;
x = 0;
int abovea = 4 ;
int belowa = 6 ;
int abovem = 4 ;
int belowm = 4 ;

      //Average

      for (int i =0 ; i<10 ; i++ ) {
      x = x + ahorse[i].gettime() ;
      }

      avg = (x / 10); 

      //Max  

      for(int i = 0 ; i < 10 ; i++){

              max = -1000;
              if ( ahorse[i].gettime() > max){
              max = ahorse[i].gettime();
               }
               }

     //Min 

      for(int i = 0 ; i < 10; i ++){

              min = 1000;
              if ( ahorse[i].gettime() < min){
                 min = ahorse[1].gettime() ;
                            }
                            }

      for(int i = 0; i < 10; i++){
              ahorse[i].print() ;
              }

      //Median   

      double median;
      if(ahorse[x].gettime() % 2 == 0){
      median = (ahorse[10].gettime() / 2) + (ahorse[10].gettime() / 2 + 1) / 2;
      }
      else{
      median = (ahorse[10].gettime() / 2) + 1;
      }



      cout << "Average: " << avg << endl;
      cout << "Fastest Time: " << min << endl;
      cout << "Slowest Time: " << max << endl;
      cout << "# Above Mean: " << abovea << endl;
      cout << "# Below mean: " << belowa << endl;
      cout << "# Above median: " << abovem << endl;
      cout << "# Below median: " << belowm << endl;
      cout << endl;

system("PAUSE");
return EXIT_SUCCESS;
}

void insertion_sort(Horse x[],int length){

Horse key;
int i;
for(int j=1;j<length;j++)
{
 key= x[j];
 i=j-1;
 while(x[i].gettime()>key.gettime() && i>=0) 
 {
           x[i+1]=x[i];
     i--;
 }
 x[i+1]=key;
}
}

Answer 1

首先，您不能使用double来下标数组，因此ahorse[x].gettime()不能工作，数组必须使用整数进行下标。想一想，ahorse[9.5]会引用什么元素？

其次，模数运算符%仅适用于整数。如果你想在双重

上做mod，请使用fmod

第三，数组从零开始索引，因此中间部分对ahorse[10]的访问是访问它之外的数组，并且作为{{的最后一个元素是无效的内存访问。 1}}数组是Horse ahorse[10]。

可能还有其他问题，但上面提到的问题是我第一眼看到的问题。

下标错误的类型无效

1 个答案: