Here’s a Java method for this:
static String checker(String no){
if(no.length()!=10) return “NO”;
try{
long n1=Long.parseLong(no);
if(no.charAt(0)==‘0’) return “NO”;
else return “YES”;
}
catch(Exception e){
return “NO”;
}
}
no -> the input telephone number
#include <iostream>
using namespace std;
int main() {
int tt;cin>>tt;
while(tt--){
string s;cin>>s;
if(s.length() == 10){
if(s[0] == '0'){
cout<<"NO"<<endl;
}else{
bool ok=true;
for(int i=0;i<10;i++){
if(s[i]-'0'>=0 && s[i]-'0'<=9){
continue;
}else{
ok=false;
break;
}
}
if(ok)
cout<<"YES"<<endl;
else
cout<<"NO"<<endl;
}
}else{
cout<<"NO"<<endl;
}
}
return 0;
}
This is the an accepted C++ code. If you are facing a problem in the solution, please first try to look at the available solutions, then ask specific doubts.