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35 lines
982 B
C++
35 lines
982 B
C++
#include <cstdio>
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typedef unsigned long long u64;
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const size_t MAXN = 1 << 16 | 1;
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bool notprime[MAXN];
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int prime[MAXN], pcnt, x;
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inline u64 fast_pow(u64 a, u64 b, u64 m)
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{
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u64 ret = 1;
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for (; b; a = a * a % m, b >>= 1)
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if (b & 1)
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ret = ret * a % m;
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return ret;
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}
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int main()
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{
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for (size_t i = 2; i < MAXN; i++)
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if (!notprime[i] && (prime[pcnt++] = int(i)))
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for (size_t j = i * i; j < MAXN; j += i)
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notprime[j] = true;
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while (~scanf("%d", &x))
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for (int a = 2, flag = 0; flag == 0; a++)
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{
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flag = 1;
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for (int i = 0, k = x - 1; i < pcnt && k > 1 && flag; i++)
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if (k % prime[i] == 0)
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{
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flag = fast_pow(a, (x - 1) / prime[i], x) != 1;
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while (k % prime[i] == 0)
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k /= prime[i];
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}
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if (flag)
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printf("%d\n", a);
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}
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return 0;
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} |