#include <iostream>
#include <cmath>
#include <set>
// Function to check if a number is prime
bool isPrime(int n) {
if (n < 2) return false;
if (n % 2 == 0) return n == 2;
int limit = sqrt(n);
for (int i = 3; i <= limit; i += 2) {
if (n % i == 0) return false;
}
return true;
}
// Function to check if all digits are unique
bool hasUniqueDigits(int n) {
std::set<int> digits;
while (n > 0) {
int d = n % 10;
if (digits.count(d)) return false; // duplicate found
digits.insert(d);
n /= 10;
}
return true;
}
int main() {
for (int num = 1000; num <= 9999; num++) {
if (isPrime(num) && hasUniqueDigits(num)) {
std::cout << "First 4-digit prime with all unique digits: " << num << std::endl;
return 0; // stop after finding the first one
}
}
std::cout << "No such number found." << std::endl;
}
/*
run:
First 4-digit prime with all unique digits: 1039
*/
