C/C++ :: Grade Converter Using Parallel Arrays

I am attempting to reconfigure a working code that before used while loops and if statements to convert a numeric score to a letter grade. I now wish to take this same code however I want to change the char convertGrade(int numScore) to simply use a parallel array as a replacement to the if statements.

The array needs to consist of 3 arrays of fixed size 5:
int minScores[SIZE]
int maxScores[SIZE]
char letterGrade[SIZE]

I know the declarations need to go in the function convertGrade but this is the first time I have worked with arrays and I am having trouble trying to figure out how this array will replace my previous if statement.

In order to access the array elements I need to write specifications such as
minScores[i]
maxScores[i]
letterGrade[i]

(where i = 0, 1, 2, 3, or 4)

#include <stdio.h>
#include <stdlib.h>
#define SIZE 5
int getScore(void);
char convertGrade(int numScore);

[Code] .....