fork download
copy 
  1. #include <bits/stdc++.h>
  2. #define ll long long
  3. #define endl "\n"
  4. #define F first
  5. #define S second
  6. #define loop(a,n) for(int i=a; i<=n ; i++)
  7. #define TIME (1.0 * clock() / CLOCKS_PER_SEC)
  8. #define NAME "sieungto"
  9. using namespace std;
  10. ll a, b, res;
  11. bool check(ll n) {
  12.     if (n < 2) return false;
  13.     if (n == 2 || n == 3) return true;
  14.     if (n % 2 == 0) return false;
  15.     for (ll i = 3; i * i <= n; i += 2)
  16.         if (n % i == 0) return false;
  17.     return true;
  18. }
  19.  
  20. ll solve(ll a, ll b) {
  21.     queue<ll> q;
  22.     q.push(2); q.push(3); q.push(5); q.push(7);
  23.     ll d = 0;
  24.     while (!q.empty()) {
  25.         ll h = q.front();
  26.         q.pop();
  27.         if (h >= a && h <= b)
  28.             d++;
  29.         if (h > b / 10) continue;
  30.         int dg[] = {1, 3, 7, 9};
  31.         for (int i = 0; i < 4; i++) {
  32.             ll next = h * 10 + dg[i];
  33.             if (check(next)) {
  34.                 q.push(next);
  35.             }
  36.         }
  37.     }
  38.     return d;
  39. }
  40. int main() {
  41.     ios_base::sync_with_stdio(0);
  42.     cin.tie(0); cout.tie(0);
  43.     freopen(NAME".INP", "r", stdin);
  44.     freopen(NAME".OUT", "w", stdout);
  45.     while (cin >> a >> b) {
  46.         res += solve(a, b);
  47.     }
  48.  
  49.     cout << res;
  50.     //cout << "Time: " << TIME << "s\n";
  51.     return 0;
  52. }
  53.  
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin
copy 
2000 7500
50 100
200 300
stdout
copy 
Standard output is empty
https://ideone.com/42DYHG
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!