Adding intergers into an array

[LiquidSolid]

Right now I need help adding numbers into an array. The function I have is not in the main function and the array parameters are passed by reference. Using something like

int add ( int grades[], int number_grades )

I need to have it so it will allow someone to input grades into the array, and using a sentinel value to stop it. The max size of the array should be 20 and use a sentinel value to stop. Finally it will count how many grades are now in the array.

[mg120]

You can add grades normally, and you can check array after adding if a[n] == sentinel you have n-1 grades.

[LiquidSolid]

I am still confused on how the code would be written out.