fatorial de grande número
class Solution {
public:
#define pb push_back
void multiply(vector<int>& arr, int no){
int carry = 0;
// Multiply each digit with the correspomding no, like in simple maths of mult.
for(int i=0;i<arr.size();i++){
int prod = arr[i] * no + carry;
arr[i] = prod % 10;
carry = prod / 10;
}
// If carry is sill there
while(carry){
arr.pb(carry % 10);
carry = carry / 10;
}
}
vector<int> factorial(int n){
// code here
vector<int>arr = {1};
// 5! = 5*4*3*2*1
// The crux here is how to multiply two numbers if it is large
for(int i=2;i<=n;i++){
multiply(arr, i);
}
// print the array or return the array
reverse(arr.begin(), arr.end());
return arr;
}
};
Viper