On Saturday, 23 July 2022 at 19:50:51 UTC, Test123 wrote:
I has this function, it print all possible combinations.
```d
void doRepetition(const int n, const int m){
// combination total number is m, element is repeatable.
assert(n >= 1 && n < 10);
assert(m >= 1 && m < 10);
enum N = 10;
ubyte[10] a;
void inc(int index, int r, int start, int end) {
if( index == r ) {
// get one unique combination result, not repeatable
for(int j =0; j < r; j++ ){
printf("%d ", a[j]);
}
printf("\n");
return ;
}
for (int i = start; i < end; i++) {
a[index] = cast(ubyte)i;
inc(index + 1, r, i, end);
}
}
inc(0, m, 0, n);
}
```
`doRepetition(4, 3);` will print
```sh
0 0
0 1
0 2
1 1
1 2
2 2
```
I need one function, print the number in reversed order like
this:
`doReverseRepetition(4, 3);` will print
```sh
2 2
1 2
1 1
0 2
0 1
0 0
```
ont solution is to put the result in array, and foreach_reverse
it. but this is slow and need a lot memory when N, M is
bigger. (9,9) will have 24310 restuls combinations. (I need
support bigger N,M late and need it fast)
Any one can help me to write a function print the reversed
order results?
On Saturday, 23 July 2022 at 19:50:51 UTC, Test123 wrote:
The give example result is `doRepetition(3, 2);`.
`doRepetition(4, 3);` restuls is:
```sh
0 0 0
0 0 1
0 0 2
0 0 3
0 1 1
0 1 2
0 1 3
0 2 2
0 2 3
0 3 3
1 1 1
1 1 2
1 1 3
1 2 2
1 2 3
1 3 3
2 2 2
2 2 3
2 3 3
3 3 3
```
N is the unique number as results combination element.
result combination total emenent number is M.
