please provide detailed solution and explanation in C language

Q18. Write a program to take input numbers from user until user enters - 1. Print the frequency of numbers from 0 to 9 that occurred in all previous inputs altogether. Do not consider - 1 and storing the user input in storages like arrays are not allowed. For example, if user entered 43534, 23354, 986, 587, 6, -1 then frequencies are: 0:0, 1:0, 2:1, 3: 4, 4:3, 5:3, 6:2, 7: 1, 8: 2, 9: 1. This means 0 occurred 0 times, I occurred 0 times, 2 occurred 1 times and so on. Assume user will enter valid inputs