git reimport

archive/2018.03/2018.03.10 - VK Cup 2018 - Round 1/TaskA.java

@@ -0,0 +1,74 @@
+package chelper;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import io.InputReader;
+import io.OutputWriter;
+import misc.SimpleSavingChelperSolution;
+
+
+public class TaskA extends SimpleSavingChelperSolution {
+
+  public void solve(int testNumber, InputReader in, OutputWriter out) {
+    wrapSolve(testNumber, in, out);
+  }
+
+  List<Integer> primes(int n) {
+    boolean[] a = new boolean[n];
+
+    List<Integer> res = new ArrayList<>();
+
+    for (int i = 2; i < n; i++) {
+      if (a[i]) {
+        continue;
+      }
+
+      res.add(i);
+
+      for (int j = i; j < n; j += i) {
+        a[j] = true;
+      }
+    }
+
+    return res;
+  }
+
+  @Override
+  public void solve(int testNumber) {
+    int N = 1100000;
+
+    List<Integer> primes = primes(N);
+
+    int x2 = in.nextInt();
+
+    int r = x2 + 1;
+    int l = x2;
+
+    for (Integer prime : primes) {
+      if (x2 % prime == 0) {
+        l = x2 - prime + 1;
+      }
+    }
+
+    int minX0 = x2;
+
+    for (Integer prime : primes) {
+      int minX1 = (l + prime - 1) / prime * prime;
+
+      if (minX1 >= r) {
+        continue;
+      }
+
+      int next = minX1 - prime + 1;
+      if (minX1 == prime) {
+        next = prime;
+      }
+
+      minX0 = Math.min(minX0, next);
+    }
+
+    out.println(minX0);
+
+  }
+}