Sorting two arrays in c++ [closed] - c++

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I need to sort two arrays (the first one, ascending; and the 2nd one descending)
Here goes the code where the sorting is done: -
for(int i=0;i<10;i++) //1st array, ascending
{
for(int j=0;j<10;j++)
{
if(array1[j]>array1[j+1])
{
int temp=array1[j];
array1[j]=array1[j+1];
array1[j+1]=temp;
}
}
} //Over
for(int i=0;i<10;i++) //2nd, descending
{
for(int j=0;j<10;j++)
{
if(array2[j]<array2[j+1])
{
int temp=array2[j];
array2[j]=array2[j+1];
array2[j+1]=temp;
}
}
} //Over
When I try printing these, it screws up somewhere and I'm unable to pinpoint the problem in the code. Thanks..

Answer 1

You can use C++ itself to sort (quite efficiently) arrays, using any valid rule you want. If you want it in ascending order, you can use the default variety, which automatically uses < effectively. If you want it in descending order, you just have to use the opposite comparison, the >.
Example:
#include <vector>
#include <algorithm>
#include <functional>
#include <iterator>
#include <iostream>
using namespace std;
int main()
{
vector<int> makeAscending = {3,2,1};
vector<int> makeDescending = {4,5,6};
sort(begin(makeAscending), end(makeAscending)); // could pass less<int>() if you wanted
sort(begin(makeDescending), end(makeDescending), greater<int>());
// print to see answer
copy(begin(makeAscending), end(makeAscending), ostream_iterator<int>(cout, " "));
cout << endl;
copy(begin(makeDescending), end(makeDescending), ostream_iterator<int>(cout, " "));
}
Just to be precise, a valid rule for sorting is one that produces a weak ordering of the items in the container. The Wikipedia page has the rules, but they are mostly this (calling any general "rule" the symbol < and x,y,z are items in your container):
1.) x < x is never true.
2.) If x < y is true that means y < x is false. (and if x < y is false and y < x is false, they are seen as "equal")
3.) if x < y is true and y < z is true then x < z is true.

Answer 2

Just had to limit the inner loop to <9.
The fixed code:
for(int i=0;i<10;i++) //1st array, ascending
{
for(int j=0;j<9;j++)
{
if(array1[j]>array1[j+1])
{
int temp=array1[j];
array1[j]=array1[j+1];
array1[j+1]=temp;
}
}
} //Over
for(int i=0;i<10;i++) //2nd array, descending
{
for(int j=0;j<9;j++)
{
if(array2[j]<array2[j+1])
{
int temp=array2[j];
array2[j]=array2[j+1];
array2[j+1]=temp;
}
}
} //Over
Thank you guys!