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  1. #include <iostream>
  2. #include <string>
  3. using namespace std;
  4.  
  5. bool palindrome(int n) {
  6.     string s=to_string(n);
  7.     int x=s.length();
  8.     for (int i=0;i<=x/2;i++) {
  9.         if (s[i]!=s[x-i-1]) {
  10.             return false;
  11.         }
  12.     }
  13.     return true;
  14. }
  15.  
  16. bool snt(int n) {
  17.     if (n<2) return false;
  18.     for (int i=2;i*i<=n;i++) {
  19.         if (n%i==0) {
  20.             return false;
  21.         }
  22.     }
  23.     return true;
  24. }
  25.  
  26. int main () {
  27.     freopen("SO.INP","r",stdin);
  28.     freopen("SO.OUT","w",stdout);
  29.     int n;
  30.     cin >> n;
  31.     int d=0;
  32.     for (int i=1;i<=n;i++) {
  33.         if (palindrome(i) && snt(i)) {
  34.             d++;
  35.         }
  36.     }
  37.     cout << d;
  38. }
  39.  
Success #stdin #stdout 0.01s 5284KB
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Standard output is empty
https://ideone.com/JJJB5N
language:
C++14 (gcc 8.3)
created:
1 day ago
visibility:
public

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