这个代码怎样改才不会TLE?

#include <bits/stdc++.h>
#include <iostream>
#include <cstdio>
using namespace std;
int n,t,r,ans=0;
int dzl(int x){
    while(x>0){
        r=x%10;
        if(r==7) return 0;
        x/=10;
    }
    return 1;
}
int main(){
	scanf("%d",&t);
    for (int i=1;i<=t;i++){
        scanf("%d",&n);
        for (int j=1;j<=n;j++){
        	if(dzl(j)==1) ans++;
		}
        printf("%d\n",ans);
		ans=0;  
    }
	return 0;
}