[BOJ] 분해합

#include<iostream>
#include<algorithm>
using namespace std;

int arr[1000005];

int main(){
    int n;
    cin >> n;
    
    int ans = 987654321;
    for(int i=1; i<=n; i++){
        arr[i] = i;

        if( i < 10 ){
            continue;
        }else if( i < 100){
            arr[i] = arr[i] + ( arr[i] / 10 % 10 );
        }else if( i < 1000){
            arr[i] = arr[i] + ( arr[i] / 100 % 10 ) + ( arr[i] / 10 % 10 ) + ( arr[i] % 10 );
        }else if ( i < 10000){
            arr[i] = arr[i] + ( arr[i] / 1000 % 10) +( arr[i] / 100 % 10 ) + ( arr[i] / 10 % 10 ) + ( arr[i] % 10 );
        }else if ( i < 100000 ){
            arr[i] = arr[i] + (arr[i] / 10000 % 10 ) + ( arr[i] / 1000 % 10) +( arr[i] / 100 % 10 ) + ( arr[i] / 10 % 10 ) + ( arr[i] % 10 );
        }else if( i < 1000000){
            arr[i] = arr[i] + (arr[i] / 100000 % 10) + (arr[i] / 10000 % 10 ) + ( arr[i] / 1000 % 10) +( arr[i] / 100 % 10 ) + ( arr[i] / 10 % 10 ) + ( arr[i] % 10 );
        }else {
            arr[i] = arr[i] + (arr[i] / 1000000 % 10) + (arr[i] / 100000 % 10) + (arr[i] / 10000 % 10 ) + ( arr[i] / 1000 % 10) +( arr[i] / 100 % 10 ) + ( arr[i] / 10 % 10 ) + ( arr[i] % 10 );
        }
        
        if( arr[i] == n){
            ans = min(ans , i);
        }
    }
    
    if( ans == 987654321)
        cout << "0" << endl;
    else
        cout << ans << endl;
    return 0;
}

#include <iostream>
using namespace std;

int cal(int num) {
    int sum = num;
    while (num!=0) {
        sum += num % 10;
        num /= 10;
    }
    return sum;
}

int main() {
    int n;
    cin >> n;
    for (int i = 1; i <= 1000000; i++) {
        if (cal(i) == n) {
            cout << i << endl;
            return 0;
        }
    }
    cout << "0" << endl;
    return 0;
}