Java : Program to find the minimum and maximum number in a given array.

/**
 * Find the minimum and maximum number in a given array. 
 * 
 * Approach: we can pick an element from array and compare with the min and max value
 * 
 *   
 */

public class MinMaxNumber {

 public static void main(String[] args) {
  
  int arr[] = {1100,10,3,5,8,1,5,9,23,56,0,90,54};
         int min,max;
         min=max= arr[0];
   for(int i =1 ; i<arr.length;i++){
    
       if (min > arr[i]){    // comparing the number for min value 
        min= arr[i];
       }
       
       if(max < arr[i]){    // comparing the number for max value
        max=arr[i];
       }
   }
   System.out.println("Min value = " + min);
   System.out.println("Max value = " + max);

 }

}

/* output
Min value = 0
Max value = 1100

Java : Program to swap two number without using any arithmetic operator

import java.util.Scanner;

/*
 * 
 * Swap two number without using any arithmetic operator like + , - etc

 * we can achieve the solution using the XOR operator
 */


public class SwapTwoNumberWithoutUsingOperator {

 public static void main(String[] args) {
  
  Scanner sc = new Scanner(System.in);
  System.out.println("Enter number A : ");
  int a = sc.nextInt();
  System.out.println("Enter number B : ");
  int b = sc.nextInt();
  
  
  System.out.println("Number before swapped A and B respectively  --> " + a +"   " + b);

  a = a^b;
  b = a^b;
  a = a^b;
  
  System.out.println("Number after swapped A and B respectively  -->  " + a +"   " + b);
  
 
 }

}

/* output
 Enter number A : 
10
Enter number B : 
30
Number before swapped A and B respectively  --> 10   30
Number after swapped A and B respectively  -->  30   10

*/

Java : Program to find the sum of each row and each column of n x m of 2D Matrix

package jun2;

/*
 * Find the sum of each row and each column of n x m of 2D Matrix 
 * 
 */

public class SumOf2DMatrixRowsAndColumn {

 
 public static void main(String[] args) {
    
  int [][] twoDMatrix = {{ 20, 18, 23, 20, 16 },
         { 30, 20, 18, 21, 20 },
         { 16, 19, 16, 53, 24 },
         { 25, 24, 22, 24, 25 }
        };
        outputArray(twoDMatrix);
    }

    public static void outputArray(int[][] array) {
        int sum= 0;
        int rowSize = array.length;
        
        int[] colSum =new int[array[0].length];
        for (int i = 0; i < array.length; i++){   
            for (int j = 0; j < array[i].length; j++){                
                sum += array[i][j];
                colSum[j] += array[i][j];
            }
            System.out.println("sum of rows "+ i +" = " + sum);
        }  
        System.out.println("  ");
        for(int k=0;k<colSum.length;k++){
            System.out.println("sum of columns "+ k +" = " + colSum[k]);
        } 
        
        
    }
 
}

/*output:

sum of rows 0 = 97
sum of rows 1 = 206
sum of rows 2 = 334
sum of rows 3 = 454
  
sum of columns 0 = 91
sum of columns 1 = 81
sum of columns 2 = 79
sum of columns 3 = 118
sum of columns 4 = 85

*/

Java : Program to find a occurrence/count of a particular pattern in a given string

/*
 * Find occurrence/count of a particular pattern in a given string .
 * For example : you have to search for a pattern ca#e or ca$e or ca&e or ca1e 
 *    where 3 character could be any thing but first 2 chars and last
 *    should contain the c ,a and e respectively.
 * 
 *   Input = "carehappyca#eforyouca$ecccaseeeeca@ca$e"
 *   output = 5
 *   
 *   Condition : You don't have to use any inbuilt function like split() or regex() function etc.
 * 
 */

public class CountPatternInStringSequence {

 
 public int countPatternInStringSequence(String str){
  
  char[] ch = str.toCharArray();  // convert the given string to character array;
  int i = 0;
  int count = 0;
  
  while(i < ch.length){
   
   if(ch[i] == 'c'){
    i++;
      if(ch[i] == 'a'){
      i= i+2;
        if(ch[i] == 'e'){
         count++;
        }else{
         i = i-2;     
        }
      }else{
      
       i = i-1;
       }
   }
   
   i = i +1;
 
  }
  return count;
 }
 
 public static void main(String[] args) {

  CountPatternInStringSequence fs = new CountPatternInStringSequence();
  String str = "carehappyca#eforyouca$ecccaseeeeca@ca$e";
  int totalCount = fs.countPatternInStringSequence(str);
  System.out.println("Given String : " + str);
  System.out.println("Total occurence of particular pattern found : " + totalCount);

 }

}

/*
output:

Given String : carehappyca#eforyouca$ecccaseeeeca@ca$e
Total occurence of particular pattern found : 5

 */

Java : A string consists of parenthesis and letters. Write a program to validate all the parenthesis.

import java.util.*;
/*
 *
 *  A string consists of parenthesis and letters. Write a program to validate all the parenthesis.
 *  Ignore the letters.eg.
 *  ((alf)ls) – valid
 *  )(dkk)() – invalid
 */

public class StringI_1 {

 public static void main(String[] args) {

  Scanner sc = new Scanner(System.in);
  System.out.print("Enter string :-  ");
  String str = sc.nextLine();
  
  System.out.println("Entered string is :-  " + str);
  
  int countOpen = 0 ;
  int countClose =0 ;
  int sizeOfString = str.length();

if(str == null || sizeOfString == 0){
            System.out.println("String is Empty");
            System.exit(0);
            } 
  
  if (str.charAt(0) != '(' && str.charAt(sizeOfString - 1) != ')' ){
   System.out.println("First : Invalid String");
   System.exit(0);
   
  }
  /*else
   System.out.println("valid");*/
  
  for(int i = 0 ; i< sizeOfString ; i++){
   
    if(str.charAt(i) == '(' && i!=(sizeOfString-1) ){
      if( str.charAt(i+1) == ')' ){
       System.out.println("Second :Invalid String ");
      System.exit(0);
      }else{
      countOpen++;
      System.out.println("countOpen :- " + countOpen +" "+ str.charAt(i));
      }
    }else {
       if(str.charAt(i) == ')' ){   //&& str.charAt(i+1) !=')'
       countClose++;
       System.out.println("countClose :- " + countClose +" "+ str.charAt(i));
      }
  } 
  }   
  if(countOpen == countClose){
   System.out.println("Valid string");
  }else{
    System.out.println("Third : Invalid String");
   }
  }
  
 }

Java : Program to reversing a string

public class ReverseString {

    /**
     * @param args
     */
    public static void main(String[] args) {
       
        //String[] name = new String[10];
        String name , rev = "";
       
        Scanner in = new Scanner(System.in);
        System.out.println("Enter the string for reversal :- ");
        name = in.nextLine();
       
        int len = name.length();
       
                for(int i = len-1;i>=0;i--){
                    rev = rev + name.charAt(i);
                }
        System.out.println(rev);
    }


}

Java : Program swapping two numbers without using third variable

public class SwapTwoNo {

    /**
     * @param args
     */
        public static  void swap(int a , int b){
           
            a = b+a;
            b = a-b;
            a = a-b;
           
            System.out.println("Values of a and b after swap := " + a +"  "+ b + " respectively");
        }   

   
        public static void main(String[] args) {
           
            int a = 5;
            int b = 6;
            System.out.println("Values of a and b before swap := " + a +"  "+ b + " respectively");
            swap(a,b);
           
        }
}