This is just an example algorithm in pseudo code to solve your problem:
0. Initialize an array container
1. Get a user input
2. Converted that input to a number
3. IF (that number is between 10 and 100 AND is not already in the array container) THEN
3.1 Add it to that array container
4. Go to 1 if that array container contains less than 10 elements.
You can use any programming language to implement this algorithm. For specific language syntaxes and features, ask Google.