inbuilt function to find factorial in c++ code example

Example 1: factorial in c++

#include<bits/stdc++.h>
#include<stdio.h>
using namespace std;

int fact(int i){
	if (i <= 1) return 1;
  	else return i*fact(i-1);
}

int main(){
  	ios::sync_with_stdio(0);
  	cin.tie(0);
  	int N;
  	cin >> N;
  	cout << fact(N) << "\n";
  	return 0;
}

Example 2: built in function in c++ for binary to decimal

#include <bits/stdc++.h>

using namespace std;

int main(void){
    bitset<8> bits("1000");
    int ab = bits.to_ulong();
    cout << ab << "\n";
    
    return 0;
}

Example 3: recursive function for fibonacci series in java javascript

var fib = function(n) {
  if (n === 1) {
    return [0, 1];
  } else {
    var arr = fib(n - 1);
    arr.push(arr[arr.length - 1] + arr[arr.length - 2]);
    return arr;
  }
};

console.log(fib(8));