1.Word count in Java?
public class WordCount{
public static void main(String[] args) {
String s = "Count the No of words in the given String. String given is ";
String array[] = s.split(" ");
List<String> arrayList = Arrays.asList(array);
Map<String, Integer> map = new HashMap<String, Integer>();
for (String string : arrayList) {
if (map.get(string) == null)
map.put(string, 1);
else
map.put(string, map.get(string) + 1);
}
System.out.println("Word Count = " + map);
}
}
O/P:
Word Count = {of=1, is=1, Count=1, given=2, words=1, String=1, String.=1, the=2, No=1, in=1}
2.How to find the duplicate number in the given integer array?
Conditions : the given string should be in sequence from 1 to n(only one number should be duplicated) .
public class DuplicateNumber{
public static void main(String[] args) {
int[] i = { 1, 2, 3, 4, 5, 6, 6, 7, 8 };
Arrays.sort(i);
int sum = 0;
for (int j = 0; j < i.length; j++) {
sum = sum + i[j];
}
int max = i[i.length - 1];
int total = max * (max + 1) / 2;
int miss = total - sum;
System.out.println(Math.abs(miss));
}
}
O/P:
The duplicated number is : 6
3. Find the count of letters in the file?
public class CountofLettersString {
public static void main(String[] args) {
String str = "CHINNA";
Map<Character, Integer> wordSet = new HashMap<Character, Integer>();
Map<Character, Integer> letterCount = new HashMap<Character, Integer>();
System.out.println("Through String");
printletterCount(str, letterCount);
System.out.println("Character" + "-->Count");
for (Character ch : letterCount.keySet()) {
System.out.println(ch + "\t--> " + letterCount.get(ch));
}
letterCount.clear();
readthefile(wordSet, letterCount);
System.out.println("Through File");
System.out.println("Character" + "-->Count");
for (Character ch : letterCount.keySet()) {
System.out.println(ch + "\t--> " + letterCount.get(ch));
}
}
public static void readthefile(Map<Character, Integer> wordSet, Map<Character, Integer> letterCount) {
Scanner wordFile = null;
String word;
try {
wordFile = new Scanner(new FileReader("words.txt"));
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
while (wordFile.hasNext()) {
word = wordFile.next();
printletterCount(word, letterCount);
}
}
public static void printletterCount(String str, Map<Character, Integer> letterCount) {
if (str != null) {
for (Character c : str.toCharArray()) {
if (c.isSpaceChar(c)) {
continue;
}
Integer count1 = letterCount.get(c);
int newCount = (count1 == null ? 1 : count1 + 1);
letterCount.put(c, newCount);
}
}
}
}
O/P:
Through String
Character-->Count
A --> 1
C --> 1
N --> 2
H --> 1
I --> 1
Through File
Character-->Count
A --> 1
C --> 1
N --> 2
H --> 1
I --> 1
4.convert string to number without using Parse method?
public class MyStringToNumber {
public static int convert_String_To_Number(String numStr) {
char ch[] = numStr.toCharArray();
int sum = 0;
int zeroAscii = '0';// Converts the char to int
for (char c : ch) {
int tmpAscii = (int) c;// converts the every character of an arry to int
sum = (sum * 10) + (tmpAscii - zeroAscii);
}
return sum;
}
public static void main(String[] args) {
System.out.println("\"3256\" == " + convert_String_To_Number(",jzxcb"));
}
}
Print 
PDF
