import java.util.*; public class test{ public static void main(String[] args){ Scanner scanner = new Scanner(System.in); int t = scanner.nextInt(); for(int i=0;i<t;i++){ long n = scanner.nextInt();//我写的int错了，囧 int weishu = 1; long temp = 0; while(temp<n){ temp += Math.pow(2, weishu); weishu++; } weishu--; temp -= Math.pow(2, weishu); long temp2 = n-temp-1; //System.out.println(weishu); //System.out.println(temp2); String s = ""; int weishu2 = 0; while(temp2!=0){ if(temp2%2==0){ s = "4"+s; weishu2++; } else{ s = "7"+s; weishu2++; } temp2 /= 2; } while(weishu2<weishu){ s = "4"+s; weishu2++; } System.out.println(s); } } } 没过，可能是输入我写的int，输入写成long估计能过，555555