leetcode - 440. 字典序的第K小数字

#include 
#include 
using namespace std;

int getSteps(int curr, long n) {
    int steps = 0;
    long first = curr;
    long last = curr;
    while (first <= n) {
        steps += min(last, n) - first + 1;
        first = first * 10;
        last = last * 10 + 9;
    }
    return steps;
}

int findKthNumber(int n, int k) {
    int curr = 1;
    k--;
    while (k > 0) {
        int steps = getSteps(curr, n);
        if (steps <= k) {
            k -= steps;
            curr++;
        } else {
            curr = curr*10;
            k--;
        }
    }
    return curr;
}

int main(){
	int n, k, res;
	cin>>n>>k;
	res = findKthNumber(n, k);
	cout<