Broken calculator (how to find factorial of big number)

#1

can i get tutorial for how can i get factorial of big number pls

#2

To solve this you have to store numbers in array.
refer to the editorial.
If you have any doubt in this do post here.
https://www.codechef.com/wiki/tutorial-small-factorials

Happy Coding :smiley:

#3

can any one explain the multiply function -

#4

int multiply(int x,int *res,int res_size){ int carry = 0,product; for(int i=0;i<res_size;i++){ product = (res[i]*x)+carry; res[i] = product%10; carry = product/10; } while(carry>0){ res[res_size] = carry%10; carry = carry/10; res_size++; } return res_size; }