assignment7-1-1_gradesorted.cpp

this code is code c++. have many lesson

#include <iostream>
#include <fstream>
#include <cstdlib>
#include <ctime>
void Bubblesort(int n[],char n2[],int size)
{
    int swap;
	int temp;
	for(int j=1;j<=size;++j)
	{
		for(int i=size; i>=1; --i)
		{
		   if(n[i]>n[i-1])
		   {
			swap=n[i-1];
			n[i-1]=n[i];
			n[i]=swap;
			temp=n2[i-1];
			n2[i-1]=n2[i];
			n2[i]=temp;
		   }
		}
     }
}
using namespace std;
int main()
{
    srand((unsigned int) time(0));
    ofstream fout("Data.txt");
    for (int i=0;i<=30;i++)
    {
        fout<<(rand()%100)+1<<endl;
    }
    fout.close();
    ifstream fin("Data.txt");
    int score; 
    int i=1;
    int num[30]={};
    char grade[30]={};
    while(fin>>score)
    {
        num[i]=score;
        if(score>=85&&score<=100)
        {
           grade[i]='A';
        }
        else if(score>=70&&score<=84)
        {
           grade[i]='B';
        }
        else if(score>=60&&score<=69)
        {
           grade[i]='C';
        }
        else if(score>=50&&score<=59)
        {
           grade[i]='D';
        }
        else 
        {
           grade[i]='F';
        }
                    ++i;                  
    }
    Bubblesort(num,grade,31);
       ofstream fout2("GradeSorted.txt");
       fout2<<"Sort of Score & Grade"<<endl;
       fout2<<"======================"<<endl;
       fout2<<"Score\tGrade\n"<<endl;
      for(int i=1;i<=30;i++)
       { 
       fout2<<num[i]<<"\t"<<grade[i]<<endl;
       }
     fout2.close();
    system("pause");
    return 0;
}