# learning alogrithms

Discussion in 'C' started by compscichick, Sep 22, 2010.

1. ### compscichickNew Member

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So the problem is to illustrate how the selection sort algorithm behaves on two inputs:
A={1,2,3,4,5} and A={5,4,3,2,1}. I need to state the output generated and then write a function for Big Oh notation.

The algorithm is:
Code:
```#include <iostream>

using namespace std;

void printout (int A [], int n)
{
for (int i=0; i<n; ++i)
cout << A[i] << " ";
cout<< '\n';
}

void selectionSort (int A[], int n)
{
for (int k=0; k<n-1; ++k) {
int tmp, index = k;
for (int i=k+1; i < n; ++i)
if (A[i] < A[index]) index=i;
tmp= A[k]; // swap
A[k] = A[index];
A [index] = tmp;
printout (A,n);
}
}
int main ()
{
system("pause");
return 0;
}
```
I thought i would need to insert a 5 in int A[5] for there being 5 vectors slots. I can get it to run and compile, but then nothing is outputted. What am I doing wrong?

2. ### jimblumbergNew Member

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In
Code:
```int main ()
{
system("pause");
return 0;
}
```
You are not doing anything but pausing. Maybe you need to set up variables, call a function or two?

Jim