git reimport

archive/2016.12/2016.12.05 - unsorted/Day5.java

@@ -0,0 +1,42 @@
+package chelper;
+
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import io.InputReader;
+import io.OutputWriter;
+
+public class Day5 {
+  public static String toHex(byte[] bytes) {
+    BigInteger bi = new BigInteger(1, bytes);
+    return String.format("%0" + (bytes.length << 1) + "x", bi);
+  }
+
+  public void solve(int testNumber, InputReader in, OutputWriter out) {
+    String s = in.nextString();
+
+    char[] res = new char[8];
+    int filled = 0;
+
+    for (int i = 0; true; i++) {
+      try {
+        String hash = toHex(MessageDigest.getInstance("MD5").digest((s + Integer.toString(i)).getBytes()));
+        if (hash.startsWith("00000")) {
+          int pos = hash.charAt(5) - '0';
+
+          if (pos >= 0 && pos < 8 && res[pos] == 0) {
+            res[pos] = hash.charAt(6);
+            filled += 1;
+            System.out.println(filled);
+            System.out.println(new String(res));
+            System.out.println();
+          }
+        }
+      } catch (NoSuchAlgorithmException e) {
+        throw new RuntimeException(e);
+      }
+    }
+  }
+}