Go: package main

/*
フィボナッチ数列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func fibWithMemo(n int, memo map[int]int) int {
	if n == 0 || n == 1 {
		return 1
	}
	if val, ok := memo[n]; ok {
		return val
	}
	memo[n] = fibWithMemo(n-1, memo) + fibWithMemo(n-2, memo)
	return memo[n]
}

func fib(n int) int {
	memo := make(map[int]int)
	return fibWithMemo(n, memo)
}

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	fmt.Println(fib(n))
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: #include <iostream>
#include <vector>
using namespace std;

vector<int> fibonacci_list(45,0);

int fibonacci(int n){
    int f;
    if(fibonacci_list.at(n)!=0){
        f=fibonacci_list.at(n);
    }else{
        f=fibonacci(n-1)+fibonacci(n-2);
        fibonacci_list.at(n)=f;
    }
    return f;
}

int main(){
    fibonacci_list.at(0)=1;
    fibonacci_list.at(1)=1;
    int n;
    cin >> n;
    cout << fibonacci(n) << endl;
    return 0;
}

C++: #include <iostream>

int dp[50];

int fib(int n) {
  if(dp[n] != -1) return dp[n];
  if(n == 0) return 1;
  if(n == 1) return 1;

  return dp[n] = fib(n-1) + fib(n-2);
}

int main() {
  int n;
  std::cin >> n;

  for(int i=0; i<50; ++i) {
    dp[i] = -1;
  }
  dp[0] = 1;
  dp[1] = 1;

  int fb = fib(n);
  std::cout << fb << std::endl;

}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef long long ll;
using namespace std;
double F[45];

int fib(int n){
    F[0]=1;F[1]=1;
    for(int i=2;i<=n;i++){
        F[i]=F[i-1]+F[i-2];
       // cout<<F[i];
    }
    return F[n];
    }

int main(){
    int a;
    cin>>a;
    cout<<fib(a)<<endl;
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
#include<utility>
#include<vector>
#include<queue>
#include<functional>
#include<map>
#include<set>
#include<cstring>
#include<string>
#include<stack>
#include<math.h>
#include<stdlib.h>
using namespace std;
//#define int long long
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<int, char> pic;
typedef priority_queue<pii, vector<pii>, greater<pii> > RPQ;
#define mk make_pair
#define INF (1 << 30)
#define INFL (1ll << 60ll)
#define mod 1000000007

int N, fib[50];

signed main(){
    fib[0] = 1;
    fib[1] = 1;
    for(int i = 2; i < 45; i++){
        fib[i] = fib[i - 1] + fib[i - 2];
    }
    cin >> N;
    cout << fib[N] << endl;


    return 0;
}

/*

*/

C++: #include <bits/stdc++.h>

#define REP( i, n) for( int i = 0; i < (n); ++i)
#define FOR( i, a, b) for( int i = (a); i < (b); ++i)

#define pb push_back

const int INF = 100100100;
const int MOD = (int)1e9 + 7;

using ll = long long;

using namespace std;

ll f( int n){
  if( n == 0) return 1;
  if( n == 1) return 1;

  return f(n-1)+f(n-2);
}

int main(){

  int x;
  

  cin >> x;
  cout << f(x) << endl;

}

C++: #include<iostream>
long dp[50];
int fib(int n){
	if (n == 0 || n == 1)
		return 1;
	else{
		if (dp[n]==0)
		    return (dp[n] = fib(n - 1) + fib(n - 2));
		else return dp[n];
	}
}
int main(){
	int n;
	std::cin >> n;
		std::cout << fib(n) << "\n";
}

C++: #include <iostream>
using namespace std;

const int MAX = 44;
int F[MAX];

int fib(int n){
  if(n==0 || n==1) return F[n];
  if(F[n] != -1) return F[n];
  return F[n] = fib(n-1) + fib(n-2);
}


int main() {
    ios::sync_with_stdio(false);

    F[0] = F[1] = 1;
    for(int i=2; i<MAX; i++) F[i] = -1;

    int n;
    cin >> n;
    cout << fib(n);
    return 0;
}

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

int F[50];

int main(){
  int n;
  cin>>n;
  F[0] = F[1] = 1;
  for(int i=2;i<=44;i++) F[i] = F[i-1]+F[i-2];
  cout<<F[n]<<endl;
  return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long
using namespace std;

int n, arr[100000];

int solve(int n) {
	arr[0]=arr[1]=1;
	for (int i = 2; i <= n; i++) arr[i] = arr[i-2]+arr[i-1];
	return arr[n];
}

int main() {
	cin >> n ;
	cout << solve(n) << endl;
}

C++: #include<iostream>
using namespace std;

int dp[44];

int fib(int n) {
	if (dp[n] != -1)return dp[n];
	int res;

	if (n == 0 || n == 1) {
		res = 1;
	}
	else {
		res = fib(n - 1) + fib(n - 2);
	}

	dp[n] = res;
	return res;
}

int main() {
	for (int i = 0; i < 44; i++) {
		dp[i] = -1;
	}
	int n;
	cin >> n;
	cout << fib(n);

	return 0;
}

C++: #include <iostream>
using namespace std;

int main(){
	int dp[50],n;
	
	cin>>n;
	dp[1]=dp[0]=1;
	for(int i=2;i<=n;i++){
		dp[i] = dp[i-1]+dp[i-2];
	}
	cout<<dp[n]<<endl;
	return 0;
}

C++: //#define _GLIBCXX_DEBUG

#include<bits/stdc++.h>
#define PI 3.14159265359
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const int INF= 1e9+5;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int>>vvi;
const ll MOD=1000000007LL;
int main(){
  int n;
  cin>>n;
  int fib[100];
  fib[0]=1;
  fib[1]=1;
  for(int i=2;i<50;i++){
    fib[i]=fib[i-1]+fib[i-2];
  }
  cout<<fib[n]<<endl;
}