题解 | #寻找丑数#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();

        int[] ans = new int[num];
        ans[0] = 1;
        int a = 0, b = 0, c = 0;
        for (int i = 1; i < num; i++) {
            ans[i] = Math.min(ans[a] * 2, Math.min(ans[b] * 3, ans[c] * 5));
            if (ans[i] == ans[a] * 2) {
                a++;
            }
            if (ans[i] == ans[b] * 3) {
                b++;
            }
            if(ans[i]==ans[c]*5){
                c++;
            }
        }
        System.out.print(ans[num-1]);

    }
}