Following code prints the factorial of number .. Problem source: https://www.hackerrank.com/challenges/extra-long-factorials/problem
[Since Factorials of Number > 20 can't be stored even in a 64-bit long long variable. Big integers must be used for such calculations.]
int main(){
int n,j=0,carry=0,a[1000]={0},i,mul,len=0;
cin >> n;
a[0]=1;
for(i=2;i<=n;i++){
for(j=0;j<=len;j++){
mul=a[j]*i+carry;
a[j]=mul%10;
carry=mul/10;
if(carry != 0 && j==len)
len++;
}
}
for(i=len;i>=0;i--){
cout << a[i];
}
return 0;
}
Can anyone explain how this code is working(proceeding)?
