Roman numerals

roman_numeralas.cpp

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using str = string;
using pii = pair<int, int>;
using vi = vector<int>;
#define dbg(v) cout << "Line(" << __LINE__ << ") -> " << #v << " = " << (v) << endl;
#define rep(i, a, n) for(int i = a; i < n; i++)
#define size(a)   (int)a.size()
#define len(a)    (int)a.length()
#define nl        '\n'
#define order(a)   sort(a.begin(), a.end())
#define rorder(a)  sort(a.rbegin(), a.rend())

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t;
    cin >> t;
    while(t--) {
        int n;
        cin >> n;
        while(n > 0) {
            if(n >= 1000) {
                cout << 'M';
                n -= 1000;
            } else if(n >= 900) {
                cout << "CM";
                n -= 900;
            } else if(n >= 500) {
                cout << 'D';
                n -= 500;
            } else if(n >= 400) {
                cout << "CD";
                n -= 400;
            } else if(n >= 100) {
                cout << 'C';
                n -= 100;
            } else if(n >= 90) {
                cout << "XC";
                n -= 90;
            } else if(n >= 50) {
                cout << 'L';
                n -= 50;
            } else if(n >= 40) {
                cout << "XL";
                n -= 40;
            } else if(n >= 10) {
                cout << 'X';
                n -= 10;
            } else if(n == 9) {
                cout << "IX";
                n -= 9;
            } else if(n >= 5) {
                cout << 'V';
                n -= 5;
            } else if(n == 4) {
                cout << "IV";
                n -= 4;
            } else if(n >= 1) {
                cout << 'I';
                n -= 1;
            }
        }
        cout << nl;
    }
}

/*
int romanToInt(string s) {
    unordered_map<char, int> m;

    m['I'] = 1;
    m['V'] = 5;
    m['X'] = 10;
    m['L'] = 50;
    m['C'] = 100;
    m['D'] = 500;
    m['M'] = 1000;

    int ans = 0;

    for(int i = 0; i < s.length(); i++){
        if(m[s[i]] < m[s[i+1]]){
            ans -= m[s[i]];
        }
        else{
            ans += m[s[i]];
        }
    }
    return ans;
}
*/