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41 lines
1.1 KiB
41 lines
1.1 KiB
#include <bits/stdc++.h>
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using namespace std;
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const int N = 1010;
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// 筛法求欧拉函数
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int primes[N], cnt;
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bool st[N];
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int phi[N];
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void euler(int n) {
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phi[1] = 1;
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for (int i = 2; i <= n; i++) {
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if (!st[i]) {
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primes[cnt++] = i;
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phi[i] = i - 1;
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}
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for (int j = 0; primes[j] * i <= n; j++) {
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st[i * primes[j]] = true;
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if (i % primes[j] == 0) {
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phi[i * primes[j]] = phi[i] * primes[j];
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break;
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}
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phi[i * primes[j]] = phi[i] * (primes[j] - 1);
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}
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}
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}
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int main() {
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// 利用筛法，预处理出欧拉函数值数组
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euler(N - 1); // 这里注意一下是N-1,防止数组越界
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int n, m;
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cin >> m;
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for (int i = 1; i <= m; i++) {
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cin >> n;
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int res = 1; // x=y 记1个
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for (int j = 1; j <= n; j++) res += phi[j] * 2; // 叠加两倍的欧拉函数值
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printf("%d %d %d\n", i, n, res);
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}
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return 0;
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} |