Ordering numbers

Pages: 12

Aug 3, 2014 at 8:29pm

Hi, I'm a beginner and I am trying to order arrays. This is what I have so far

#include <iostream>

using namespace std;

int main()
{
    int arr[4];
    int t;
    int ar[4]{35,11,36,47};
    /*if(ar[0]<ar[1]){ar[0]=arr[1];ar[1]=arr[0];};
    for(int i=1; i<4; i++)
    {
        t=i+1;
        if (ar[i]>arr[t]){arr[i]=ar[t];arr[t]=ar[i];}
        else {arr[i]=ar[i];arr[t]=ar[t];};

    }
    for(int d=0;d<4; d++)
    {
        cout<<arr[d]<<",";
    }*/
    if(ar[0]<ar[1])
        {
            ar[0]=arr[1];
            ar[1]=arr[0];
        }

    else
    {
        arr[1]=ar[0];
        arr[1]==ar[0];
    }

    if(arr[1]<ar[2])
    {
        t=ar[2];
        arr[1]=ar[2];
        arr[2]=t;
    }

    else
        {
            arr[1]=ar[0];
            arr[1]==ar[0];
        }

    if(arr[2]<ar[3])
        {
            t=ar[3];
            arr[2]=ar[3];
            arr[3]=t;
        }

    else
        {
            arr[1]=ar[0];arr[1]==ar[0];
        }

    if(arr[4]<ar[3])

        {
            t=ar[4];
            arr[3]=ar[4];
            arr[4]=t;
        }

    else
        {
            arr[1]=ar[0];arr[1]==ar[0];
        }

        for(int d=0;d<4; d++)
    {
        cout<<arr[d]<<",";
    }


    return 0;
}

Edit & run on cpp.sh

the commented part is the part that I tried to use a for loop instead of hard coding it, but it didn't work. can you help me by giving me an example and its even better if you can help me on the for loop.

thanks

Last edited on Aug 3, 2014 at 8:30pm

Aug 3, 2014 at 8:55pm

admkrk (505)

I would suggest doing a search for Sorting algorithms so that you get a better understanding of what is involved as there are several ways to do it. There are a few examples here:https://www.cs.cmu.edu/~adamchik/15-121/lectures/Sorting%20Algorithms/sorting.html

The biggest thing you are doing wrong with what you have is that you are not swapping the values like you think you are.

1
2
3

//ar[0] = 35, ar[1] = 11
ar[0]=ar[1]; // ar[0] = 11
ar[1]=ar[0]; // ar[1] = 11

You need to have a temp variable to swap

1
2
3

temp = ar[0]; // temp = 35
ar[0] = ar[1]; // ar[0] = 11
ar[1] = temp; //ar[1] = 35

Last edited on Aug 3, 2014 at 8:57pm

Aug 5, 2014 at 2:23am

Dexter 3202 (27)

can you do it using a for loop and not hard code it

Aug 5, 2014 at 2:57am

Dexter 3202 (27)

this still doesnt work

#include <iostream>

using namespace std;

int main()
{
int arr[4];
int t;
int ar[4]{35,11,36,47};
/*if(ar[0]<ar[1]){ar[0]=arr[1];ar[1]=arr[0];};
for(int i=1; i<4; i++)
{
t=i+1;
if (ar[i]>arr[t]){arr[i]=ar[t];arr[t]=ar[i];}
else {arr[i]=ar[i];arr[t]=ar[t];};

}
for(int d=0;d<4; d++)
{
cout<<arr[d]<<",";
}*/
if(ar[0]<ar[1])
{
t = ar[0];
ar[0] = ar[1];
ar[1] = t;
}

else
{
arr[1]=ar[0];
arr[1]==ar[0];
}

if(arr[1]<ar[2])
{
t=ar[2];
arr[1]=ar[2];
arr[2]=t;
}

else
{
arr[1]=ar[0];
arr[1]==ar[0];
}

if(arr[2]<ar[3])
{
t=ar[3];
arr[2]=ar[3];
arr[3]=t;
}

else
{
arr[1]=ar[0];arr[1]==ar[0];
}

if(arr[4]<ar[3])

{
t=ar[4];
arr[3]=ar[4];
arr[4]=t;
}

else
{
arr[1]=ar[0];arr[1]==ar[0];
}

for(int d=0;d<4; d++)
{
cout<<arr[d]<<",";
}

return 0;
}

Last edited on Aug 5, 2014 at 2:58am

Aug 5, 2014 at 3:00am

Dexter 3202 (27)

can you give me a whole sample program???

Aug 5, 2014 at 4:39am

TwilightSpectre (1392)

The really easy way - use a sorting function:

#include <iostream>
#include <algorithm>

int main() {
    const unsigned int arrsize = 4;

    int arr[arrsize] = {35, 11, 36, 47};
    std::sort(arr, arr + arrsize);

    for (unsigned int i = 0; i < arrsize; ++i)
        std::cout << arr[i] << ' ';

    return 0;
}