large inputs

guys help me out here ,whenever there is an input that is order of 10^6 or 10^9 my compiler says runtime error…when i check the solution like in the ‘ODD’ problem one guy has used character array and then converted them into integers…i mean how do i handle large inputs

Please do NOT ask mulitple times -, you can always edit your question

please post your code so that it would be better to understand why you are getting the runtime error