Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rev(i, n) for(int i = (int)(n - 1); i >= 0; i--)
#define rev1(i, n) for(int i = (int)(n); i > 0; i--)
#define pb push_back
#define all(v) ((v).begin(), (v).end())
using ll = long long;
using P = pair<int, int>;
/* ------------------------------------------------ */
ll fact(int i) {       //階乗
    if (i == 0) return 1;
    return (fact(i - 1)) * i;
}
ll gcd(ll a, ll b) {        //最大公約数
    if(b == 0) return a;#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rev(i, n) for(int i = (int)(n - 1); i >= 0; i--)
#define rev1(i, n) for(int i = (int)(n); i > 0; i--)
#define pb push_back
#define all(v) ((v).begin(), (v).end())
using ll = long long;
using P = pair<int, int>;
/* ------------------------------------------------ */
ll fact(int i) {       //階乗
    if (i == 0) return 1;
    return (fact(i - 1)) * i;
}
ll gcd(ll a, ll b) {        //最大公約数
    if(b == 0) return a;
    return gcd(b, a % b); 
}
ll lcm(ll a, ll b) {      //最小公倍数
    return a * b / gcd(a, b);
}
int keta(ll n) {        //桁数を求める
    if(n == 0) return 1;
    int count = 0;
    while(n != 0) {
        n /= 10;
        count++;
    }
    return count;
}
ll ketasum(ll n) {    //各桁の和
    ll sum = 0;
    while(n != 0) {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}
/* ------------------------------------------------ */

int main() {
    ll x;
    cin >> x;
    ll i = 0;
    ll n = 100;
    while(n < x) {
        i++;
        n+=n/100;
    }
    cout << i << endl;
    return 0;
}
    return gcd(b, a % b); 
}
ll lcm(ll a, ll b) {      //最小公倍数
    return a * b / gcd(a, b);
}
int keta(ll n) {        //桁数を求める
    if(n == 0) return 1;
    int count = 0;
    while(n != 0) {
        n /= 10;
        count++;
    }
    return count;
}
ll ketasum(ll n) {    //各桁の和
    ll sum = 0;
    while(n != 0) {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}
/* ------------------------------------------------ */

int main() {
    ll x;
    cin >> x;
    ll i = 0;
    ll n = 100;
    while(n < x) {
        i++;
        n*=1.01;
    }
    cout << i << endl;
    return 0;
}

Compiler output:
a.cc:17:25: error: stray '#' in program
   17 |     if(b == 0) return a;#include <bits/stdc++.h>
      |                         ^
a.cc: In function 'll gcd(ll, ll)':
a.cc:17:26: error: 'include' was not declared in this scope
   17 |     if(b == 0) return a;#include <bits/stdc++.h>
      |                          ^~~~~~~
a.cc:17:35: error: 'bits' was not declared in this scope
   17 |     if(b == 0) return a;#include <bits/stdc++.h>
      |                                   ^~~~
a.cc:17:40: error: 'stdc' was not declared in this scope; did you mean 'std'?
   17 |     if(b == 0) return a;#include <bits/stdc++.h>
      |                                        ^~~~
      |                                        std
a.cc:18:1: error: expected primary-expression before 'using'
   18 | using namespace std;
      | ^~~~~
a.cc:28:16: error: a function-definition is not allowed here before '{' token
   28 | ll fact(int i) {       //階乗
      |                ^
a.cc:32:20: error: a function-definition is not allowed here before '{' token
   32 | ll gcd(ll a, ll b) {        //最大公約数
      |                    ^
a.cc:36:20: error: a function-definition is not allowed here before '{' token
   36 | ll lcm(ll a, ll b) {      //最小公倍数
      |                    ^
a.cc:39:16: error: a function-definition is not allowed here before '{' token
   39 | int keta(ll n) {        //桁数を求める
      |                ^
a.cc:48:18: error: a function-definition is not allowed here before '{' token
   48 | ll ketasum(ll n) {    //各桁の和
      |                  ^
a.cc:58:9: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
   58 | int main() {
      |         ^~
a.cc:58:9: note: remove parentheses to default-initialize a variable
   58 | int main() {
      |         ^~
      |         --
a.cc:58:9: note: or replace parentheses with braces to value-initialize a variable
a.cc:58:12: error: a function-definition is not allowed here before '{' token
   58 | int main() {
      |            ^