This problem can be solved using a recursive approach. Here is a step-by-step explanation of how to implement the function in C++:

1. First, we need to handle the base cases. If the target is 0, we return true because we can always form a sum of 0 without using any elements. If the size of the array is 0 and the target is not 0, we return false because we can't form a non-zero sum without any elements.

```cpp
if (target == 0) return true;
if (size == 0) return false;
```

2. Next, we consider two possibilities for each element in the array: either we include it in the sum or we don't. We use recursion to explore both possibilities.

```cpp
bool include = combinations(array, size - 1, target - array[size - 1]);
bool exclude = combinations(array, size - 1, target);
```

3. If either of the recursive calls returns true, we return true. Otherwise, we return false.

```cpp
return include || exclude;
```

4. Finally, we put everything together into a function:

```cpp
bool combinations(int array[], int size, int target) {
if (target == 0) return true;
if (size == 0) return false;
bool include = combinations(array, size - 1, target - array[size - 1]);
bool exclude = combinations(array, size - 1, target);
return include || exclude;
}
```

This function works by recursively exploring all possible combinations of elements in the array. It stops as soon as it finds a combination that sums to the target, or if it has explored all combinations without finding a valid one.

Question

This problem can be solved using a recursive approach. Here is a step-by-step explanation of how to implement the function in C++:

1. First, we need to handle the base cases. If the target is 0, we return true because we can always form a sum of 0 without using any elements. If the size of the array is 0 and the target is not 0, we return false because we can't form a non-zero sum without any elements.

```cpp
if (target == 0) return true;
if (size == 0) return false;
```

2. Next, we consider two possibilities for each element in the array: either we include it in the sum or we don't. We use recursion to explore both possibilities.

```cpp
bool include = combinations(array, size - 1, target - array[size - 1]);
bool exclude = combinations(array, size - 1, target);
```

3. If either of the recursive calls returns true, we return true. Otherwise, we return false.

```cpp
return include || exclude;
```

4. Finally, we put everything together into a function:

```cpp
bool combinations(int array[], int size, int target) {
    if (target == 0) return true;
    if (size == 0) return false;
    bool include = combinations(array, size - 1, target - array[size - 1]);
    bool exclude = combinations(array, size - 1, target);
    return include || exclude;
}
```

This function works by recursively exploring all possible combinations of elements in the array. It stops as soon as it finds a combination that sums to the target, or if it has explored all combinations without finding a valid one.

Knowee AI · Accepted Answer