java

[Solved] Splitting a String which has longitude and latitude points

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If we can guarantee that the String to parse is always defined in a canonical way, so that is defined as lat+long ALWAYS, then using regex will be the easiest way: Example: String latLong = “lat/lng: (55.94569390835889,-3.190410055779333)”; Pattern patte = Pattern.compile(“-?[0-9]+(?:.[0-9]+)?”); Matcher matcher = patte.matcher(latLong); while (matcher.find()) { System.out.println(Double.parseDouble(matcher.group())); } solved Splitting a String which … Read more

[Solved] Java incrementing every character in a string by a large amount?

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First I’m going to remove all of the I/O (except for outputting the result), get rid of the decryption piece for brevity, and write encrypt(String) and encrypt(char) as pure functions. public class EncryptionMain { public static void main(String args[]){ System.out.println(encrypt(“Hello”)); } static String encrypt(String plaintext) { StringBuilder ciphertext = new StringBuilder(plaintext); for (int i = … Read more

[Solved] Teaching the computer to play texas Hold’em poker [closed]

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The complexity and state space of the Poker is not large. Therefore it is possible to just exhaustively search all the combinations. In fact you can even calculate the probability of getting each cards with some arithmetic. I would recommend you to read Poker Theory and Analytics by Kevin Desmond on MIT Open Courseware to … Read more

[Solved] Counting down or Counting up, Which one is faster? [duplicate]

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Never wonder; use Google Caliper to find out. Since there has been quite a bit of discussion around the relative weights of testing against zero vs. upper limit and incrementing vs. decrementing, here’s the Cartesian product of all these cases: import java.util.Random; import com.google.caliper.Runner; import com.google.caliper.SimpleBenchmark; public class Performance extends SimpleBenchmark { static final Random … Read more

[Solved] How to get the 3rd digit of a four-digit Integer?

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In anticipation that it will be needed, here is how you get all the digits of a number. long value = Long.MAX_VALUE; System.out.println(value); while (value != 0) { // get the remainder when divided by 10 int digit = (int) (value % 10); System.out.print(digit + ” “); // now divide value by 10 to position … Read more

[Solved] How to add two int array values together?

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This kinda works. I can think of a couple of cases where something like this would break, like if the arrays were like {9,9,9} and {9,9,9}, result would be {9,9,8} instead of {1,9,9,8}. It’s a minor fix that is being left as an activity to the reader. public static void main(String []args){ int[] number1 = … Read more

[Solved] Why does this statement work in Java?

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The second statement is valid: System.out.println((grade/=3) + “%”); Here the (grade/=3) is calculated first and then % is appended. But the System.out.println((“Apples”) System.out.println(“Oranges”)); is invalid statement. For this case compiler generates compilation errors like : error: ‘)’ expected error: illegal start of expression error: ‘;’ expected solved Why does this statement work in Java?