i have to make a program where a user inputs one number and i have to find the number of a certain amount of number in the program.
for example:
user input: 2349354787839
output: There are two sevens
i know it has the use of loops but i am having trouble finding a way to scan each individual digit in the input to find if it is a seven or not. or maybe i have the wrong idea...
can someone help me out?
I'd try a char array for input. In the loop body, test for the desired number and increment a count variable.
Code:if char_arr[loop_index] equals some_digit // increment count;
The thing is we cant use arrays yet because we havent learned them. is there a way to do this with just loops?
You could use scanf, inside a loop.
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loop while your input is greater than zero. Check into the modulus operator for finding the digit, compare that value against the target number for counting, and lastly use division on the input to control the loop. There's a certain number base you can use.
Show your code if you're still stuck.
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Simply use getchar() and check each digit if it's the one you are looking for.
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Just do a linear search, it's an O(n) time algorithm but will do the work for you, better if you use Binary Search, it has O(log n) complexity and very efficient for large number of input.Originally Posted by Tommy Kim
Binary search is not applicable here.
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That depends on how large you want allow the number that the user enter's to be. As it is, for your example you need to resort to the largest integer type there is. ([unsigned] long long)
If you want it to be allowed to be really huge, then sorry an array is the only option.
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