#3564. 「NOIP2021」报数

https://loj.ac/s/1479129

LibreOJ/3564/3564.cpp

@@ -0,0 +1,59 @@
+#include <algorithm>
+#include <fstream>
+#include <utility>
+
+std::ifstream cin("number.in");
+std::ofstream cout("number.out");
+const char endl = '\n';
+
+int t, x, ans[200005];
+bool f[10000005];
+std::pair<int, int> q[200005];
+
+bool has7(int x) {
+    while (x) {
+        if (x % 10 == 7) return true;
+        x /= 10;
+    }
+
+    return false;
+}
+
+int main() {
+    cin >> t;
+
+    for (int i = 7; i <= 10000000; i += 7) {
+        f[i] = true;
+    }
+
+    for (int i = 1; i <= 10000000; i++) {
+        if (has7(i)) {
+            for (int j = 1; i * j <= 10000000; j++) {
+                f[i * j] = true;
+            }
+        }
+    }
+
+    for (int i = 0; i < t; i++) {
+        cin >> q[i].first;
+        q[i].second = i;
+    }
+
+    std::sort(q, q + t);
+
+    for (int i = 0, j = 1; i < t; i++) {
+        if (f[q[i].first]) {
+            ans[q[i].second] = -1;
+            continue;
+        }
+        while (j <= q[i].first) j++;
+        while (j <= 10000000 && f[j]) j++;
+        ans[q[i].second] = j;
+    }
+
+    for (int i = 0; i < t; i++) {
+        cout << ans[i] << endl;
+    }
+
+    return 0;
+}