FunctionIter | Topcoder Archive

Problem Statement

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You will be given a int[] f describing a function (0-indexed). The value of the function on input k is f[k] (element k of f). To iterate a function you keep calling it on itself. For example, to iterate f 5 times on input x, you would evaluate

     f(f(f(f(f(x))))).

Return the smallest number n larger than bound, such that iterating f n times on x evaluates to x.

Definition

Class:: FunctionIter
Method:: compute
Parameters:: int[], int, int
Returns:: int
Method signature:: int compute(int[] f, int bound, int x)
(be sure your method is public)

Constraints

f will contain between 1 and 50 elements inclusive.
Each element of f will be between 0 and k-1 inclusive, where k is the number of elements in f.
bound will be between 0 and 10000 inclusive.
x will be between 0 and k-1 inclusive, where k is the number of elements in f.
There will be a solution.

Examples

```
{0,1,2,3,4,5}
```
```
2
```
```
4
```
```
Returns: 3
```
Everything is mapped to itself by f. Simply return the first value after bound.
```
{1,2,3,4,5,6,0}
```
```
3
```
```
1
```
```
Returns: 7
```
1->2->3->4->5->6->0->1 7 steps needed to return to 1.

{9,9,4,4,5,6,7,18,7,10,3,4,2,8,1,3,12,3,1,1,0,0,0}

Returns: 792

```
{0}
```
```
10000
```
```
0
```
```
Returns: 10001
```
```
{0}
```
```
0
```
```
0
```
```
Returns: 1
```

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