'commit'

TangDou/LuoGuBook/P5723_Test_1.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+const int N = 1000000;
+int prime[N];
+
+int main() {
+    int idx;
+    int flag;
+    for (int i = 2; i < N; i++) {
+        flag = 1;
+        for (int j = 2; j * j < i; j++) //会快很多
+//        for (int j = 2; j < sqrt(i); j++)
+            if (i % j == 0) flag = 0;
+        if (flag == 1) prime[idx++] = i;
+    }
+    printf("%.2f", (double) clock() / CLOCKS_PER_SEC);
+    return 0;
+}