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  1. #include <algorithm>
  2. #include <iostream>
  3. #include <set>
  4. #include <string>
  5.  
  6. using namespace std;
  7.  
  8. int main() {
  9.     const set<int> primes{2, 3, 5, 7};
  10.     string num;
  11.     cin >> num;
  12.     num.erase(remove_if(begin(num), end(num), [&](char c){ return !primes.count(c - '0'); }), end(num));
  13.     cout << num << '\n';
  14. }
Success #stdin #stdout 0s 16056KB
comments (?)
stdin 
420171523
stdout 
27523
https://ideone.com/J982F1
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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