پاسخ داده شده: تعریف متغیر در c
جهت محاسبه فاکتوریل اعداد بزرگ از آرایه به صورت زیر استفاده کنید:
// C++ program to compute factorial of big numbers #include<iostream> using namespace std; // Maximum number of digits in output #define MAX 500 int multiply(int x, int res[], int res_size); // This function finds factorial of large numbers // and prints them void factorial(int n) { int res[MAX]; // Initialize result res[0] = 1; int res_size = 1; // Apply simple factorial formula n! = 1 * 2 * 3 * 4...*n for (int x=2; x<=n; x++) res_size = multiply(x, res, res_size); cout << "Factorial of given number is n"; for (int i=res_size-1; i>=0; i--) cout << res[i]; } // This function multiplies x with the number // represented by res[]. // res_size is size of res[] or number of digits in the // number represented by res[]. This function uses simple // school mathematics for multiplication. // This function may value of res_size and returns the // new value of res_size int multiply(int x, int res[], int res_size) { int carry = 0; // Initialize carry // One by one multiply n with individual digits of res[] for (int i=0; i<res_size; i++) { int prod = res[i] * x + carry; // Store last digit of 'prod' in res[] res[i] = prod % 10; // Put rest in carry carry = prod/10; } // Put carry in res and increase result size while (carry) { res[res_size] = carry%10; carry = carry/10; res_size++; } return res_size; } // Driver program int main() { factorial(100); return 0; }