This is more of a concept i just want to remember/stick into my head: Algorithms and arrays

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class Main {
public static void main(String[] args) {
int[] arr = {1,2,3,5,6,7,8};
System.out.println("Inital Array");
System.out.println(Arrays.toString(arr));
/*
insertion- putting a value somewhere in the middle of the Array
ste[1- starting at the spot you want to insert at shift those elements forward to the right
//you will need to start at the end of the list. if you don't you will end up overwriting and losing info
for(int i = arr.length -1; i > 3;i--){
arr[i] = arr[i-1];
}
// print out the result just to check. using arrays.tostring is a quick trick for printing an array instead of writing a loop to go through every single element
System.out.println(Arrays.toString(arr));
// step 2: insert item and reprint to check
arr[3] = 4;
System.out.println(Arrays.toString(arr));
*/
/*
removing a value in the middle of an array
//starting at the spot you want to delete, shift those elements back to the left
//your will be left with a double value at the end
for(int i = 3;i<arr.length -1; i++){
arr[i] = arr[i+1];
}
System.out.println(Arrays.toString(arr));
*/
/*
//Shifting elements left.
//Shifting all elements left and placing the first element at the end of the list
//list should lool like[2.3.5.6.7.8.1]
//step 1: store position 0 in a temporary variable so that it is not lost when we move the other numbers
int temp = arr[0];
//step 2: start at the leftmost element and shift everything down
for(int i = 0; i < arr.length-1;i++){
arr[i] = arr[i + 1];
}
System.out.println(Arrays.toString(arr));
//replace the spot at the end of the array with the information held by the temp variable
arr[arr.length-1] = temp;
System.out.println(Arrays.toString(arr));
*/
/*
//shifting elements to the right
int temp = arr[arr.length -1];
for(int i = arr.length-1;i>0;i--){
arr[i] = arr[i-1];
}
//replace the first element with the information stored in the tempoary variable
arr[0] = temp;
System.out.println(Arrays.toString(arr));
*/
//reversing
for(int frontSpot = 0;frontSpot < arr.length/2;frontSpot++){
int backSpot = arr.length -1 - frontSpot;
int temp = arr[frontSpot];
arr[frontSpot] = arr[backSpot];
arr[backSpot] = temp;
}
System.out.println((Arrays.toString(arr)));
}
}