Test stringhe ed array

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.fscotto</groupId>
+    <artifactId>interviewdemo</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.6.1</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <source>14</source>
+                    <target>14</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    
+</project>

src/main/java/org/fscotto/interview/demo/InterviewQuestionsC1.java

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+package org.fscotto.interview.demo;
+
+import java.util.*;
+
+public class InterviewQuestionsC1 {
+
+    public static boolean isUniqueChars(final String str) {
+        if (str == null || "".equals(str))
+            return false;
+
+        if (str.length() > 128)
+            return false;
+
+        final boolean[] charSet = new boolean[128];
+        for (int i = 0; i < str.length(); ++i) {
+            int val = str.charAt(i);
+            if (charSet[val])
+                return false;
+            charSet[val] = true;
+        }
+        return true;
+    }
+
+    public static boolean permutation(final String s, final String t) {
+        if (s == null || t == null || s.length() != t.length())
+            return false;
+
+        final int[] letters = new int[128];
+        final char[] sArray = s.toCharArray();
+        for (final char c : sArray)
+            letters[c]++;
+
+        for (int i = 0; i < t.length(); i++) {
+            final int c = t.charAt(i);
+            letters[c]--;
+            if (letters[c] < 0)
+                return false;
+        }
+        return true;
+    }
+
+    public static void replaceSpaces(char[] str, int trueLength) {
+        int spaceCount = 0;
+        for (int i = 0; i < trueLength; i++) {
+            if (str[i] == ' ') {
+                spaceCount++;
+            }
+        }
+
+        int index = trueLength + spaceCount * 2;
+        if (trueLength < str.length)
+            str[trueLength] = '\0';
+        for (int i = trueLength - 1; i >= 0; --i) {
+            if (str[i] == ' ') {
+                str[index - 1] = '0';
+                str[index - 2] = '2';
+                str[index - 3] = '%';
+                index -= 3;
+            } else {
+                str[index - 1] = str[i];
+                index--;
+            }
+        }
+    }
+
+    public static boolean palindrome(String str) {
+        
+        return false;
+    }
+
+}

src/test/java/org/fscotto/interview/demo/InterviewQuestionsC1Test.java

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+package org.fscotto.interview.demo;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class InterviewQuestionsC1Test {
+
+    @Test
+    void isUniqueCharsTests() {
+        assertFalse(InterviewQuestionsC1.isUniqueChars(null));
+        assertFalse(InterviewQuestionsC1.isUniqueChars(""));
+        assertTrue(InterviewQuestionsC1.isUniqueChars("a"));
+        assertTrue(InterviewQuestionsC1.isUniqueChars("abc"));
+        assertFalse(InterviewQuestionsC1.isUniqueChars("anna"));
+        assertFalse(InterviewQuestionsC1.isUniqueChars("birbante"));
+        assertFalse(InterviewQuestionsC1.isUniqueChars(getStringAllASCII()));
+    }
+
+    private String getStringAllASCII() {
+        StringBuilder sb = new StringBuilder(130);
+        for (int i = 0; i < 129; ++i)
+            sb.append((char) i);
+        return sb.toString();
+    }
+
+    @Test
+    void isPermutationOfTests() {
+        assertFalse(InterviewQuestionsC1.permutation(null, "BAC"));
+        assertFalse(InterviewQuestionsC1.permutation("BAC", null));
+        assertFalse(InterviewQuestionsC1.permutation(null, null));
+        assertTrue(InterviewQuestionsC1.permutation("", ""));
+        assertTrue(InterviewQuestionsC1.permutation("ABC", "BAC"));
+        assertTrue(InterviewQuestionsC1.permutation("BAC", "ABC"));
+        assertTrue(InterviewQuestionsC1.permutation("BAC", "CAB"));
+    }
+
+    @Test
+    void replaceSpacesTests() {
+        final char[] str = "Mr John Smith    ".toCharArray();
+        InterviewQuestionsC1.replaceSpaces(str, 13);
+        assertEquals("Mr%20John%20Smith", new String(str));
+    }
+
+
+
+}