Bucket sort with huge random numbers - c++

Question

I know Bucket sort is has a lot of examples everywhere, so I tried to implement this so it can take huge random numbers with no luck
void Bucket_sort(int arr[], int max){
const int maxsize = max;
int bucket_list = new int [maxsize+1];
int length = sozeof(bucket_list) / sizeof(bucket[0]);
for(int i = 0; i <max;i++){
bucket_list[i] = 0; //fill with zeros
}
for (unsigned int i = 0; i <length; i++){
bucket_list[arr[i]]++;
}
int position = 0;
for (unsigned int i = 0 i < length; i++){
for(int k = 0; k<bucket_list[i];k++){
arr[position++] = i;
}
}
}
int main() {
int max = 50000
int arr[max];
for (int i = 0; i < max; i++){
arr[i] = rand() % 50000;
}
cout<<"Here are the numbers before Bucker Sort"<<endl;
for (int j = 0; j < max; j++){
cout<<arr[j];
}
Bucket_sort(arr,max);
for (int k = 0; k<max; k++){
cout<<arr[k];
}
}
some how I can't get it working, it will just out put the same order (unsorted)
I did find some same questions as mine, but none of them helped, here is one
https://stackoverflow.com/questions/20037176/c-bucket-sort-putting-integers-into-buckets

Answer 1

This line:
bucket_list = 0; //fill with zeros
this is changing your pointer, not filling with zeros. You should use
bucket_list[i] = 0; //fill with zeros
Edit: There are a lot more compiler issues with your code. Once you have those sorted out, the calculation of length is still wrong. You can't use the sizeof dividing trick, because bucket_list isn't an array. Replace
int length = sozeof(bucket_list) / sizeof(bucket[0]);
with
int length = maxsize
or just don't use length at all (you already have maxsize).

Answer 2

#include<iostream>
#include<conio.h>
#include<stdlib.h>
using namespace std;
void Bucket_sort(int arr[], int max){
int maxsize = max;
int *bucket_list = new int[maxsize+1];
// int length = sozeof(bucket_list) / sizeof(bucket[0]);
int length = maxsize;
for(int i = 0; i <max;i++){
bucket_list[i] = 0; //fill with zeros
}
for (unsigned int i = 0; i <length; i++){
bucket_list[arr[i]]++;
}
int position = 0;
for (unsigned int i = 0 ; i < length ; i++){
for(int k = 0; k<bucket_list[i];k++){
arr[position++] = i;
}
}
}
int main() {
int max = 50;
int arr[max];
for (int i = 0; i < max; i++){
arr[i] = rand()%50;
}
cout<<"Here are the numbers before Bucker Sort"<<endl;
for (int j = 0; j < max; j++){
cout<<arr[j];
}
Bucket_sort(arr,max);
for (int k = 0; k<max; k++){
cout<<arr[k];
}
getch();
return 0;
}