public/subjects/foldint.en.md

## foldint

## **WARNING! VERY IMPORTANT!**

For this exercise a function will be tested **with the exam own main**. However the student **still needs** to submit a structured program:

This means that:

- The package needs to be named `package main`.
- The submitted code needs one declared function main(```func main()```) even if empty.
- The function main declared needs to **also pass** the `Restrictions Checker\`(illegal functions tester). It is advised for the student to just empty the function main after its own testings are done.
- Every other rules are obviously the same than for a `program`.

### Instructions

Write a function called `FoldInt` that simulates the behavior of reduce from JavaScript.

The function should have as parameters a function, `f func(int, int) int` a slice of integers, `slice []int` and an int `acc int`. You should apply for each element of the slice the arithmetic function, saving and printing it. The function will be tested with our own functions `Add, Sub, and Mul`.

### Expected function

```go
func FoldInt(f func(int, int) int, slice []int, acc int) {

}
```

### Usage

Here is a possible program to test your function:

```go
package main

func main() {
  table := []int{1, 2, 3}
  ac := 93
  FoldInt(Add, table, ac)
  FoldInt(Mul, table, ac)
  FoldInt(Sub, table, ac)
  fmt.Println()
  
  table = []int{0}
	FoldInt(Add, table, ac)
	FoldInt(Mul, table, ac)
	FoldInt(Sub, table, ac)
}

```

And its output :

```console
student@ubuntu:~/[[ROOT]]/test$ go build
student@ubuntu:~/[[ROOT]]/test$ ./test
99
558
87

93
0
93
student@ubuntu:~/[[ROOT]]/test$
```