Occurences of numbers and alphabets using structure of arrays

[cpplearn]

to find the quantity of the form of each number / char appeared in this file. The form of a number means positive and negative valued number, or lower- and uppercase letters.

if the text file has 1 -1 2 -2 2 2 A c K it should display as

Number Positive Negative
1 1 1
2 3 1

Char lower Upper
A 0 1
c 1 0
K 0 1

#include<iostream>
#include<fstream>   //Reading the file
#include<string>    //using the string datatype
using namespace std;
struct num_det
{ 
	int number;               //Defining the structure as per therequirement
	unsigned short positive;       
	unsigned short negative;
}stru_arr[100];
void insert_stru(num_det[],int,unsigned short&);   //Function signature
int main()
{
	string filename;
	int num[100],temp;
	unsigned short ind=0,k=0,pos_count=0,neg_count=0;
	ifstream inpt_file;
	cout<<"Please enter the full path or file name present in the current working:";
	cin>>filename;
	inpt_file.open(filename);
	while(inpt_file>>temp)
	{
	  num[ind]=temp;          //reading the file
	  ind++;
	}
	for(int i=0;i<ind;i++)
	 {
	    temp=num[i];
		 if(num[i]<0)
			 temp*=-1;          
	 insert_stru(stru_arr,temp,k);  //Moving the absolute values and distinct once into structure array.
     }
	for(int i=0;i<k;i++)
	{
		for(int j=0;j<ind;j++)
		{
			if(stru_arr[i].number==num[j])
			  ++pos_count;
			if((stru_arr[i].number*-1)==num[j])
			  ++neg_count;
		}
	 stru_arr[i].positive=pos_count;          //found positive instance
	 stru_arr[i].negative=neg_count;     //found negative instance
	 pos_count=neg_count=0;            //resetting back the counters
	}
	cout<<"Number\tPositive\tNegative"<<endl;
	for(int i=0;i<k;i++)
	    cout<<stru_arr[i].number<<"   \t"<<stru_arr[i].positive<<"  \t\t"<<stru_arr[i].negative<<endl;  //Displaying the output structural array
	
	system("pause");
	return 0;
}
void insert_stru(num_det stru_arr[],int temp,unsigned short &k)
{
	bool flag=true;
	for(int i=0;i<k;i++)
	{
		if(stru_arr[i].number==temp)     //Find the distinct one or not.
				flag=false;
	}
	if(flag)
	{
	stru_arr[k].number=temp;       //Distinct scenario found.
	k++;
	}
}

I just done with the number part but bit confusing about the alphabets?? any help