51 lines
758 B
C++
51 lines
758 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int max_n = 1e7;
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char is_prime[max_n + 1];
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void sieve() {
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for (int i = 0; i <= max_n; i++)
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is_prime[i] = 1;
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is_prime[0] = 0;
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is_prime[1] = 0;
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// 2 check
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for (int i = 4; i <= max_n; i += 2)
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is_prime[i] = 0;
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// other
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for (int i = 3; i * i <= max_n; i += 2)
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if (is_prime[i])
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for (int j = i * i; j <= max_n; j += i)
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is_prime[j] = 0;
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}
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int solve() {
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int n;
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cin >> n;
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if (!is_prime[n])
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return 0;
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int digit_sum = 0;
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while (n) {
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digit_sum += n % 10;
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n /= 10;
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}
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if (!is_prime[digit_sum])
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return 0;
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return 1;
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}
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int main() {
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sieve();
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int q;
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cin >> q;
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int res = 0;
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while (q--) {
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res += solve();
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}
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cout << res << "\n";
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}
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