fast interger input Algorithm
The fast integer input algorithm is a highly efficient method for reading large amounts of integer data from standard input streams, such as files or console input. This algorithm is designed to minimize the time and resources required for parsing integers, making it a valuable tool for competitive programming and other situations where performance is crucial. Traditional methods like scanf() or cin in C++ can be slow and inefficient when dealing with a high volume of integer data, which is where the fast integer input algorithm shines.
The fast integer input algorithm leverages several optimization techniques to achieve its high performance. Firstly, the algorithm reads input data in large chunks, reducing the overhead of repeatedly calling slower input functions. Secondly, the algorithm employs bitwise operations, which are significantly faster than standard arithmetic operations. Lastly, the algorithm often makes use of pointer manipulation and low-level data structures, such as character arrays, to further minimize the overhead and maximize the speed of reading and parsing integers. By combining these optimizations, the fast integer input algorithm can quickly parse large volumes of integer data, making it an indispensable tool in competitive programming and other performance-critical applications.
// Read integers in the fastest way in c plus plus
#include<iostream>
void fastinput(int *number) {
// variable to indicate sign of input integer
bool negative = false;
register int c;
*number = 0;
// extract current character from buffer
c = std::getchar();
if (c == '-') {
// number is negative
negative = true;
// extract the next character from the buffer
c = std::getchar();
}
// Keep on extracting characters if they are integers
// i.e ASCII Value lies from '0'(48) to '9' (57)
for (; (c > 47 && c < 58); c = std::getchar())
*number = *number *10 + c - 48;
// if scanned input has a negative sign, negate the
// value of the input number
if (negative)
*(number) *= -1;
}
// Function Call
int main() {
int number;
fastinput(&number);
std::cout << number << "\n";
return 0;
}
