合法字符串 + 函数合理运用

#include<bits/stdc++.h>
using namespace std;
int id[10]={7,0,1,3,2,9,4,6,8,5};
int cha(char s){
    int s1=s-'0';
    return id[s1];
}
bool dfs(char k[],int len){
    int sum=0;
    for(int i=0;i<len;i++){
        if(k[i]>='0' and k[i]<='9')
        sum+=cha(k[i]);
        else return false;
    }
    if(sum%17<=5) return false;
    return true;
}
int main(){
	int n;
    cin>>n;
    char id[1001];
    int tmp=1;
    for(int i=1;i<=n;i++){
        cin>>id;
        if(!dfs(id,strlen(id))){cout<<id<<endl; tmp=0;}
    }
    if(tmp) cout<<"all ok";
    return 0;
}