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58 lines
1.4 KiB
C++
58 lines
1.4 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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const long long N = 6000010;
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const long long mod = 1000000007;
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long long n, m, k, t;
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long long ans, powk[N], vis[N], f[N], pri[N], tot;
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long long qpow(long long a, long long b) {
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long long res = 1;
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while (b) {
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if (b & 1) res = res * a % mod;
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a = a * a % mod;
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b >>= 1;
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}
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return res;
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}
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void euler(long long n) {
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f[1] = 1;
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vis[1] = 1;
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for (long long i = 2; i <= n; i++) {
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if (!vis[i]) pri[++tot] = i, f[i] = (powk[i] - 1 + mod) % mod;
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for (long long j = 1; j <= tot && i * pri[j] <= n; ++j) {
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vis[i * pri[j]] = 1;
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if (i % pri[j] == 0) {
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f[i * pri[j]] = f[i] * powk[pri[j]] % mod;
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break;
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} else {
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f[i * pri[j]] = f[i] * f[pri[j]] % mod;
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}
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}
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}
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}
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int main() {
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cin >> t >> k;
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for (long long i = 1; i <= 5000000; i++) {
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powk[i] = qpow(i, k);
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}
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euler(5000000);
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for (long long i = 1; i <= 5000000; i++) {
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f[i] = (f[i] + f[i - 1]) % mod;
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}
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while (t--) {
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cin >> n >> m;
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ans = 0;
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for (long long l = 1, r; l <= min(n, m); l = r + 1) {
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r = min(n / (n / l), m / (m / l));
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ans += (n / l) * (m / l) % mod * ((f[r] - f[l - 1] + mod) % mod) % mod;
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ans %= mod;
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}
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cout << ans << endl;
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}
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return 0;
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} |