20 lines
451 B
C++
20 lines
451 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 1000000;
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int prime[N];
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int main() {
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int idx;
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int flag;
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for (int i = 2; i < N; i++) {
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flag = 1;
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for (int j = 2; j * j < i; j++) //会快很多
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// for (int j = 2; j < sqrt(i); j++)
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if (i % j == 0) flag = 0;
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if (flag == 1) prime[idx++] = i;
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}
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printf("%.2f", (double) clock() / CLOCKS_PER_SEC);
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return 0;
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}
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