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Problem of the day

You are given an array * 'arr'* of size

Find the number of ways of selecting the elements from the array such that the sum of chosen elements is equal to the target 'k'.

Since the number of ways can be very large, print it modulo 10 ^ 9 + 7.

```
Input: 'arr' = [1, 1, 4, 5]
Output: 3
Explanation: The possible ways are:
[1, 4]
[1, 4]
[5]
Hence the output will be 3. Please note that both 1 present in 'arr' are treated differently.
```

Detailed explanation

```
4 5
1 4 4 5
```

```
3
```

```
The possible ways are:
[1, 4]
[1, 4]
[5]
Hence the output will be 3. Please note that both 1 present in 'arr' are treated differently.
```

```
3 2
1 1 1
```

```
3
```

```
There are three 1 present in the array. Answer is the number of ways to choose any two of them.
```

```
3 40
2 34 5
```

```
0
```

```
The expected time complexity is O('n' * 'k').
```

```
1 <= 'n' <= 100
0 <= 'arr[i]' <= 1000
1 <= 'k' <= 1000
Time limit: 1 sec
```