- Added Java solution to "Middle 3-digits" task of week 135.

1 files changed, 52 insertions, 0 deletions

diff --git a/challenge-135/mohammad-anwar/java/MiddleThreeDigits.java b/challenge-135/mohammad-anwar/java/MiddleThreeDigits.java
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+++ b/challenge-135/mohammad-anwar/java/MiddleThreeDigits.java
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+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/*
+
+Week 135:
+
+    https://theweeklychallenge.org/blog/perl-weekly-challenge-135
+
+Task #1: Middle 3-digits
+
+    You are given an integer.
+
+    Write a script find out the middle 3-digits of the given integer, if possible otherwise throw sensible error.
+
+*/
+
+class MiddleThreeDigits {
+
+    public static void main(String[] args) {
+        String p = System.getProperty("number", "1234567");
+
+        Pattern pattern = Pattern.compile("\\-?\\d+");
+        if (pattern.matcher(p).find()) {
+
+            int n = Math.abs(Integer.parseInt(p));
+            int l = countDigits(n);
+            if (l == 1) {
+                System.out.println("ERROR: Too short.");
+            }
+            else if (l % 2 == 0) {
+                System.out.println("ERROR: Even number of digists.");
+            }
+            else {
+                int i = (l / 2) - 1;
+                System.out.println(String.valueOf(n).substring(i, i+3));
+            }
+
+        }
+        else {
+            System.out.println("ERROR: Invalid number.");
+        }
+    }
+
+    public static int countDigits(int n) {
+        int l = 0;
+        for(; n != 0; n /= 10, ++l);
+        return l;
+    }
+
+}