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OI-codes/S2OJ/1023/1023.cpp

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#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
int t, n, m, phi[1000005], cnt, prime[1000005];
bool vis[1000005];
void euler(int n) {
phi[1] = 1;
for (int i = 2; i <= n; i++) {
if (!vis[i]) {
phi[i] = i - 1;
prime[++cnt] = i;
}
for (int j = 1; j <= cnt; j++) {
if (1ll * i * prime[j] >= n) break;
vis[i * prime[j]] = true;
if (i % prime[j]) {
phi[i * prime[j]] = phi[i] * (prime[j] - 1);
} else {
phi[i * prime[j]] = phi[i] * prime[j];
break;
}
}
}
}
int find(int l, int r, int x) {
int res = 0;
while (l <= r) {
int mid = (l + r) >> 1;
if (prime[mid] >= x) {
res = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
return res;
}
int main() {
std::ios::sync_with_stdio(false);
cin >> t;
euler(1000000);
while (t--) {
memset(vis, 0x00, sizeof(vis));
cin >> m >> n;
if (n <= 1000000) {
int l = find(0, cnt, m);
for (int i = l; i <= cnt; i++) {
if (prime[i] > n) break;
cout << prime[i] << endl;
}
} else {
int l = m + (m & 1);
if (l == 2) l += 2;
for (int i = l; i <= n; i += 2) {
vis[i - m] = true;
}
int d = sqrt(n) + 1;
for (int i = 2; i <= cnt; i++) {
if (prime[i] > d) break;
int p = (m - 1) / prime[i] + 1;
p += !(p & 1);
if (p == 1) p += 2;
for (int j = p; j * prime[i] <= n; j++) {
vis[j * prime[i] - m] = true;
}
}
for (int i = m; i <= n; i++) {
if (!vis[i - m]) {
cout << i << '\n';
}
}
}
cout << endl;
}
return 0;
}