Go: package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)

	x, y := int64(0), int64(1)
	for i := 0; i < n; i++ {
		x, y = y, x+y
	}

	fmt.Println(x)
}

C++: #include <algorithm>
#include <iostream>
#include <queue>
#include <cmath>
#include <string>
#include <iterator>
#include <map>
#include <set>
#include <iomanip>
#include <vector>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using Graph = vector<vector<int>>;
int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};
#define INF 100000000
#define MAX 200001
#define MOD 1000000007
ll fac[MAX], finv[MAX], inv[MAX];
const int MX = 1000005;

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

C++: #include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")

#define rep(i,n) for(int i = 0;i<n;i++)
const long long MOD = 1000000007;

int main(){
  int n; cin >> n;
  long long fib[n+1];
  fib[0] = 1; fib[1] = 1;
  for(int i = 2; i<=n;i++){
    fib[i] = fib[i-1] + fib[i-2];
  }
  cout << fib[n] << "\n";
}

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

int fiboArray[44] = {0};
int fibonacci(int anySection) {
	if (anySection == 0 || anySection == 1)
		return (fiboArray[anySection] = 1);

	if (fiboArray[anySection] == 0) { //?¨?????????????????????????
		fiboArray[anySection] = fibonacci(anySection - 1) + fibonacci(anySection - 2);
		return fiboArray[anySection];
	}
	else //?????§????¨?????????????????????????
		return fiboArray[anySection];
}

int main() {
	int anySection;
	cin >> anySection;

	int answer = fibonacci(anySection);

	cout << answer << endl;
	return 0;
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>
#include<utility>
#include<numeric>
#include<iostream>
#include<array>
#include<string>
#include<sstream>
#include<stack>
#include<queue>
#include<list>
#define _USE_MATH_DEFINES

#include<math.h>
#include<map>

#define SENTINEL 1000000001

#define min(a,b) (a)>(b)?(b):(a)
#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

int main()
{
	int fib[50];
	fib[0] = 1;
	fib[1] = 1;

	for (int i = 2; i < 50; i++)
	{
		fib[i] = fib[i - 1] + fib[i - 2];
	}

	int n;
	cin >> n;

	cout << fib[n] << endl;

	return 0;
}

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

int main(){
    int N;
    cin >> N;

    // F[0] から F[N] までのメモリを確保
    // 初期値 0 ，N + 1 コの要素
    vector<ll> dp(N+1, 0);

    // 初期条件，フィボナッチ数列の初期値 F[0] と F[1] は 1
    dp[0] = 1;
    dp[1] = 1;

    // 配列 dp の遷移を行う
    for (int i=2; i<=N; i++){
        // 現在の項以前の 2 項を足す処理
        dp[i] += dp[i-1];
        dp[i] += dp[i-2];
        // cout << i << " : " << dp[i] << endl;
    }

    cout << dp[N] << endl;
    return 0;
}

C++: #include<cstdio>
int F[46];
int fib(int flag){
	if(flag<2){
		return 1;
	}else if(F[flag]){
		return F[flag];
	}else{
		return F[flag]=fib(flag-1)+fib(flag-2);
	}
}
int main(){
	int num;
	scanf("%d", &num);
	printf("%d\n", fib(num));
	return 0;
}

C++: #include <algorithm>
#include <cmath>
#include <ctime>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#include <cstring>
#include <tuple>
#include <bitset>
#include <unordered_map>
using namespace std;
typedef long long ll;
int main() {
    ios::sync_with_stdio(false);

    vector<int> fib(50);
    fib[0] = fib[1] = 1;
    for (int i=2; i<50; ++i) {
        fib[i] = fib[i-1] + fib[i-2];
    }

    int n;
    cin >> n;
    cout << fib[n] << endl;

    return 0;
}

C++: #include <iostream>

int F[50];
int main() {
    int n;
    scanf("%d", &n);

    for (int i = 0; i <= n; i++) {
        if (i <= 1) F[i] = 1;
        else {
            F[i] = F[i-1] + F[i-2];
        }
    }
    printf("%d\n", F[n]);
}

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

#define rep(i, a, n)  for(ll i=a; i<n; i++)
#define per(i, a, n)  for(ll i=n-1; i>=a; i--)
#define fill0(n)  setfill('0') << right << setw(n)
#define all(x)  (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define LONGMAX 1e18
#define INTMAX 1000000000

using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
const ll mod = 1e9+7;
const long double EPS = 0.0000000001;


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

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
//#include "MyMath.h"
//#include "MyDisjointset.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <functional>
#include <stdio.h>
#include <math.h>
#include <string.h>
using namespace std;
typedef pair<int, int> P; typedef long long int ll;
const int INF = 100000000;
int mod = 10000;
vector <vector<int> > mul(vector<vector<int> > f, vector<vector<int> > s) {
	vector<vector<int> > res(2, vector <int> (2) );
	res[0][0] = (f[0][0] * s[0][0] + f[0][1] * s[1][0]) % mod;
	res[0][1] = (f[0][0] * s[0][1] + f[0][1] * s[1][1]) % mod;
	res[1][0] = (f[1][0] * s[0][0] + f[1][1] * s[1][0]) % mod;
	res[1][1] = (f[1][0] * s[0][1] + f[1][1] * s[1][1]) % mod;
	return res;
}
int main() {
	int n; cin >> n;
	vector<vector<int> > base(2, vector<int> (2) );
	base[0][0] = 1;
	base[0][1] = 1;
	base[1][0] = 1;
	base[1][1] = 0;
	vector<vector<int> > ans(2, vector<int>(2));
	ans[0][0] = 1;
	ans[0][1] = 0;
	ans[1][0] = 0;
	ans[1][1] = 1;
	while (n > 0) {
		if (n & 1) ans = mul(ans, base);
		//cout << ans[0][0] << " " << ans[0][1] << endl;
		//cout << ans[1][0] << " " << ans[1][1] << endl;
		//cout << endl;
		base = mul(base, base);
		n >>= 1;
	}
	cout << ans[1][0] + ans[1][1]  << endl;
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define ms(s,x) memset(s,x,sizeof(s))
#define ls rt<<1
#define rs rt<<1|1
#define pb push_back
#define inf 0x3f3f3f3f
#define IOS ios::sync_with_stdio(false)
typedef long long ll;
using namespace std;

const double PI = acos(-1.0);
const double eps = 1e-8;
const int MAXN = 1e5+5;
const ll MOD = 1e9+7;
const int N = 1e5;

int main()
{
    ll fib[45] = {1, 1};
    int n;
    cin >> n;
    rep(i, 2, n){
        fib[i] = fib[i-1] + fib[i-2];
    }
    cout << fib[n] << endl;

    return 0;
}

C++: #include <iostream>
#include <vector>

using lli = long long int;
std::vector<lli> vec;
int main() {
    int n;
    std::cin >> n;
    vec.assign(n+1, 0);
    vec[0] = 1;
    vec[1] = 1;
    for (int i = 2; i <= n; i++) {
        vec[i] = vec[i-1] + vec[i-2];
    }
    std::cout << vec[n] << std::endl;

}

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

int main() {
	int n; cin >> n;
	vector<int> F(50, 0);

	F[0] = 1;
	for (int i = 0; i < n; ++i) {
		F[i + 1] += F[i];
		F[i + 2] += F[i];
	}

	cout << F[n] << endl;
}

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

int f[45];
int n;

int fibonacci(int n){
	
	cin >> n;
	f[0]=f[1]=1;

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


int main(){
	cout << fibonacci(n) << "\n";
    return 0;
}

C++: #include <iostream>
using ll = long long;
using namespace std;
#define MAX 50
/* initialize */
int fibs[MAX];

/* main */
int main() {

    int n;
    cin >> n;
    fibs[0]=fibs[1] = 1;
    for (int i = 2; i <= n; i++) {
        fibs[i] = fibs[i-1] + fibs[i-2];
    }
    cout << fibs[n] << "\n";
    return 0;
}