How to read a vector of characters from stdout or until user presses enter or not

#1

suppose i have to read characters in order of pow(10,18)

#2

First of all , you cannot read input from stdout.
stdout stands for standard output. You can print your output to stdout whereas read the input from the stdin ( standard input ).
As for reading the characters , you can use cin to input a string which would read the entire string or run a loop to take input till EOF.
Also since you want to take such large inputs , I would suggest you to use fast input-output for a better performance.

#3

yes i know by mistake wrote it , stdin meant “in” means input from stdin. btw my doubt was reading a vector of characters from stdin wth capacity pow(10,18) but it gives a runtime error bad_alloc meaning it cannot allocate memory it has nothing to do with time http://ideone.com/4pD208 so how to read 10^18 size vector

#4

@RishabhSingh
C++ simply does not allow you to create an array of size larger than 10^9. That is the maximum we can go , be it static allocation or dynamic. Since a vector too uses a dynamic array only , it gives a bad_alloc exception when you try to declare such a large array. It is simply not allowed in C++.

#5

so is there any way to store something greater than 10^9 char arrays,strings or anything.

#6

since the chewbacca problem says it can have 10^18

#7

@RishabhSingh
10^18 means that the number is just 18 digits long. You can take its input in long long int variable or a string. Both would work and this problem can be solved either way.
I only said that you cannot make an array of size 10^18. But if you need to store a single number of order of 10^18 then you can just use a long long int variable or make an array of 18 size if you wish to store each digit seperately.

#8

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