allocation error in c++ - c++

Question

I have this following code to sort number which I read from text file. My text file elements must be like this:
3 6
6
5
1
The first number (3) in the first column represents the number of elements that should I sort, the first number in second column represent the max number which I have to send via array which is 6 here.
And the number must be sorted is 6 5 1.
So this is my code but there is error says "invalid allocation size" and how to send max via array.
I need help please.
Here is my code:
// Read and Sort.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<iostream>
#include<fstream>
using namespace std ;
#include<time.h>
#include <string>
int Max ;
int number_of_items;
const int s= 22;
int arr[s];
int n=sizeof(arr)/sizeof(*arr);
class sort{
public:
int read_file()
{
int num = 0;
int x ;
char filename[50];
ifstream numbersfile ;
cout<<"Please enter the file name below"<<endl<<"_______________________________________________"<<endl;
cin.getline(filename,50);
cout<<"_______________________________________________"<<endl;
numbersfile.open(filename);
if(numbersfile.is_open())
{
for(int i =0;i<n;i++){
numbersfile>>arr[i];
Max=arr[0];
number_of_items=arr[1];
}
}
else{
cout<<"Failed To load requierd file"<<endl;
}
int arr2[s];
cout<<"The elements supposed to be sorted are:"<<endl<<endl;
for(int i =2;i<n;i++){
numbersfile>>arr[i];
cout<<arr[i]<<" "<<endl;
}
counting_sort(arr2,n);
return 0 ;}
int counting_sort(int arr[],int size)
{
int n=size;
int max=arr[0];
for (int i=1;i<n;i++) {
if (arr[i]>max) {
max=arr[i];
}
}
int *output_array=new int[n];
for (int i=0;i<n;i++) {
output_array[i]=0;
}
int *count=new int[max+1];
for (int i=0;i<=max+1;i++) {
count[i]=0;
}
for (int i=0;i<n;i++){
count[arr[i]]=count[arr[i]]+1;
}
for (int i=1;i<max+1;i++) {
count[i]=count[i]+count[i-1];
}
for (int i=n-1;i>=1;i--) {
output_array[count[arr[i]]-1]=arr[i];
count[arr[i]]=count[arr[i]]-1;
}
cout<<"The sorted elements are:"<<endl<<endl;
for (int i=0;i<n;i++) {
cout<<output_array[i]<<" ";
}
cout<<"\n-----------------------------------------------"<<endl;
return 0;
}
};
int _tmain(int argc, _TCHAR* argv[])
{
clock_t t1,t2;
t1=clock();
sort s1;
s1.read_file();
t2 = clock();
float diff = ((float)t2 - (float)t1)/1000 ;
cout <<"The time taken to execute this process is:\n"<< diff<<" Milliseconds." << endl;
return 0;
}

Answer 1

int *count=new int[max+1];
for (int i = 0; i <= max+1;i++) {
count[i]=0;
}
Note that here you goes out of range, because you try to access the last element as count[max+1], because the <= in the conditional test, and this position is not allocated. It should be like this:
int *count=new int[max+1];
for (int i = 0; i < max+1;i++) {
count[i]=0;
}
I suggest to you to carefully check each for, looking if you aren't accessing some position not bounded/allocated. Use printf's or cout's to debug, this is really useful.