Hi there. I'm new to the merge sort, but this is day four and I can't for the life of me figure out why this code won't sort my vector. I use CodeBlocks.
When compiled, it simply outputs the array it it's scattered order. I don't understand why it executes the function, yet apparently does nothing at the same time. ANY help is appreciated, thank you so much!
#include <iostream>
#include <vector>
#include <conio.h>
#include <time.h>
#include <stdlib.h>//random number gen
using namespace std;
vector <int> c;
void merge(vector <int>,int, int , int );
void mergesort(vector <int> a, int low, int high)
{
int mid;
if (low < high)
{
mid=(low+high)/2;
mergesort(a,low,mid);
mergesort(a,mid+1,high);
merge(a,low,high,mid);
}
return;
}
void merge(vector <int> a, int low, int high, int mid)
{
int i, j, k;
i = low;
k = low;
j = mid + 1;
while (i <= mid && j <= high)
{
if (a[i] < a[j])
{
c[k] = a[i];
k++;
i++;
}
else
{
c[k] = a[j];
k++;
j++;
}
}
while (i <= mid)
{
c[k] = a[i];
k++;
i++;
}
while (j <= high)
{
c[k] = a[j];
k++;
j++;
}
for (i = low; i < k; i++)
{
a[i] = c[i];
}
}
int main()
{
srand (time(NULL));
vector <int> a;
vector<int> b;
for (int i=0; i<10000; i++)
c.push_back(0);
int i;
for (int i=0; i<10000; i++)
a.push_back(rand()%2147483647);
mergesort(a, 0, 9999);
cout<<"This is not okay. Is it actually done the merge func? What has happened...\n";
getch();
cout<<"sorted array\n";
for (i = 0; i < 10000; i++)
{
cout<<c[i]<<endl;//NOTE that I keep changing this from 'c' to 'a' because I wanted to see if it sorted either. It didn't...
}
getch();
}
