Code:
#include iostream
using namespace std;
// A function to print all combination of a given length from the given array.
void Combination(int a[], int reqLen, int start, int currLen, bool check[], int len)
{
// Return if the currLen is more than the required length.
if(currLen > reqLen)
return;
// If currLen is equal to required length then print the sequence.
else if (currLen == reqLen)
{
cout<<"\t";
for (int i = 0; i < len; i++)
{
if (check[i] == true)
{
cout<
}
}
cout<<"\n";
return;
}
// If start equals to len then return since no further element left.
if (start == len)
{
return;
}
// For every index we have two options.
// First is, we select it, means put true in check[] and increment currLen and start.
check[start] = true;
Combination(a, reqLen, start + 1, currLen + 1, check, len);
// Second is, we don't select it, means put false in check[] and only start incremented.
check[start] = false;
Combination(a, reqLen, start + 1, currLen, check, len);
}
int main()
{
int i, n;
bool check[n];
cout<<"Enter the number of element array have: ";
cin>>n;
int arr[n];
cout<<"\n";
// Take the input of the array.
for(i = 0; i < n; i++)
{
cout<<"Enter "<
cin>>arr[i];
check[i] = false;
}
// For each length of sub-array, call the Combination().
for(i = 1; i <= n; i++)
{
cout<<"\nThe combination of length "<
Combination(arr, i, 0, 0, check, n);
}
return 0;
}
Output:
The combination of length 1 for the given array set:
a
b
c
d
e
The combination of length 2 for the given array set:
a b
a c
a d
a e
b c
b d
b e
c d
c e
d e
The combination of length 3 for the given array set:
a b c
a b d
a b e
a c d
a c e
a d e
b c d
b c e
b d e
c d e
The combination of length 4 for the given array set:
a b c d
a b c e
a b d e
a c d e
b c d e
The combination of length 5 for the given array set:
a b c d e
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