C-Plus-Plus/others/fast_interger_input.cpp at master · SelfCodeLearning/C-Plus-Plus · GitHub

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// 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;

*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;

}

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