Idiot Programmer

 Program for the power of the number using recursion in java Code: import java.util.Scanner; public class Test{ public static void main(String[] args) { Scanner scn = new Scanner(System.in); System.out.println(power(6,3)); } public static int power(int n,int pow){ if(pow==1){ return n; } return n * power(n,pow-1); } } or == import java.util.Scanner; public class Test{ public static void main(String[] args) { Scanner scn = new Scanner(System.in); System.out.println(power(2,10)); } public static int power(int n,int pow){ if(pow==1){ return n; } if(n==0){ return 0; } if(pow%2==0){ return power(n,pow/2) * power(n,pow/2); }else{ return power(n,pow/2) * power(n,pow/2) * n; } } }

 program for printing the fibonacci series upto n using recursion in java Code:: import java.util.Scanner; public class Test{ static int a=0,b=1,c; public static void main(String[] args) { Scanner scn = new Scanner(System.in); System.out.println("Enter the number "); int n = scn.nextInt(); if(n==1){ System.out.println(0); }else if(n==2){ System.out.println(0+" "+1); }else{ System.out.print(0+" "+1+" "); fib(n-2); } } public static void fib(int n){ if(n==0){ System.out.println(); return; } c = a+b; a = b; b = c; System.out.print(c+" "); fib(n-1); } }

 Program for factorial of the number using recursion in java Code: import java.util.Scanner; public class Test{ public static void main(String[] args) { Scanner scn = new Scanner(System.in); int n = scn.nextInt(); System.out.println(fact(n)); } public static int fact(int n){ if(n==1){ return 1; } return n * fact(n-1); } }

 program for printing the 1 to n using recursion in java Code: import java.util.Scanner; public class Test{ public static void main(String[] args) { Scanner scn = new Scanner(System.in); int n = scn.nextInt(); print(n); } public static void print(int n){ if(n==0){ return; } print(n-1); System.out.println(n); } } i/p: 5 o/p: 1 2 3 4 5

 program for the sum of n numbers using recursion in java Code: import java.util.Scanner; public class Test{ public static void main(String[] args) { Scanner scn = new Scanner(System.in); int n = scn.nextInt(); System.out.println(sum(n)); } public static int sum(int n){ if(n==0){ return 0; } return n + sum(n-1); } } i/p: 5 o/p: 15 i/p: 10 o/p: 55

 find the nearest prime number in java The closest prime can be greater or smaller than the passed input integer. If there are equi-distant  prime-numbers, print both. Example: Input#1: 32 Output#1: 31 Input#2: 30 Output#2: 29 31 Code:: import java.util.Scanner; public class Test { public static void main(String[] args) { Scanner scn = new Scanner(System.in); int n = scn.nextInt(); find(n); } public static void find(int num) { // greater number int num1 = num + 1; while (true) { if (isPrime(num1)) { break; } num1++; } // smaller int num2 = num - 1; while (num2 > 1) { if (isPrime(num2)) { break; } num2--; } // System.out.println(num1+" "+num2); if (num2 == 1) { System.out.println(num1); } else if (num1 - num == num - num2) { System.out.println(num2 + " " + num1); } else if (num1 - num < num - num2) { System.out.println(num1); } else { System.out.println(num2)...

how to iterate hashmap in java  for explanation watch video:: 1) import java.util.*; public class Test{   public static void main(String args[])  {   HashMap<Integer,String> hm = new HashMap<>(); hm.put(1,"raja"); hm.put(2,"ram"); hm.put(3,"mohan"); hm.put(4,"roy"); for(Map.Entry<Integer,String> e : hm.entrySet()){ System.out.println(e.getKey() + " "+e.getValue()); } }    }  2) Code: import java.util.*; public class Test{   public static void main(String args[])  {   HashMap<Integer,String> hm = new HashMap<>(); hm.put(1,"raja"); hm.put(2,"ram"); hm.put(3,"mohan"); hm.put(4,"roy"); //keys for(int i : hm.keySet()){ System.out.print(i+" "); } System.out.println(); for(String s : hm.values()){ System.out.print(s+" "); } System.out.println(); }    }  3) import java.util.*...

 Binary Search program in java Program: import java.util.*; import java.lang.*; import java.io.*; class Test{ public static void main(String[] args){ int[] arr = {-8,-3,-1,5,7,9}; System.out.println(bin(arr,5)); } public static int bin(int[] arr,int num){ int s = 0; int e = arr.length-1; while(s<=e){ int mid = (s+e)/2; if(num==arr[mid]){ return mid; }else if(num > arr[mid]){ s = mid+1; }else{ e = mid-1; } } return -1; } } Recursive  ======= Code: import java.util.*; import java.lang.*; import java.io.*; class Codechef{ public static void main(String[] args){ int[] arr = {-8,-3,-1,5,7,9}; System.out.println(rec(5,arr,0,arr.length-1)); } public static int rec(int val,int[] arr,int s,int e){ if(s<=e){ int mid = (s+e)/2; int cmp = arr[mid]; if(cmp == val){ return mid; }else if(cmp > val){ return rec(val,arr,s,mid-1); }else{ return rec(val,arr,mid+1,e); ...

 java program for finding the nth fibonacci number using recursion Code:: import java.util.*; import java.lang.*; import java.io.*; class Test{ public static int fib(int n){ if(n<=1){ return n; } return fib(n-1) + fib(n-2); } public static void main(String[] args){ System.out.println(fib(7)); } }  o/p::  13 0 -> 0th fib num 1-> 1st fib num 1 -> 2nd fib num 2 -> 3rd fib num 3....>4th 5...->5th 8->6th 13-> 7th

 binary to decimal conversion code in java Code: import java.util.*; import java.lang.*; import java.io.*; class Test{ public static void main(String[] args){ Scanner scn = new Scanner(System.in); System.out.println("Enter the Binary Number : "); int bin = scn.nextInt(); deci(bin); } public static void deci(int bin){ int res = 0; int i = 0; while(bin!=0){ int r = bin%10; res = res + (r*(int)Math.pow(2,i)); i++; bin = bin/10; } System.out.println(res); } } ex: input : 1010 o/p:  10 input : 1000 o/p: 8 i/p: 10101 o/p: 21

 Decimal to Hexadecimal Conversion Code:: import java.util.*; import java.lang.*; import java.io.*; class Test{ public static void main(String[] args){ Scanner scn = new Scanner(System.in); int dec = scn.nextInt(); hexa(dec); } public static void hexa(int dec){ String hexa = "0123456789ABCDEF"; String res = ""; while(dec!=0){ int r = dec%16; res = hexa.charAt(r) + res; dec = dec/16; } System.out.println(res); } } ex:: hexadecimal Number :: F Decimal Number :: 15 hexadecimal number : 1A decimal number : 26

Population Census hackerrank Solution for explanation watch video: Code:: select sum(city.population) from city inner join country on CITY.CountryCode = COUNTRY.Code where country.CONTINENT = 'Asia';

  Valid Parentheses Question Solution in java Code:  import java.util.*; class Test { public static void main(String[] args){ Scanner scn = new Scanner(System.in); String s = scn.next(); System.out.println(isValid(s)); } public static boolean isValid(String s) {        Stack<Character> st = new Stack<>();         for(int i=0;i<s.length();i++){             char ch = s.charAt(i);             if(ch=='('||ch=='['||ch=='{'){                 st.push(ch);             }else if(st.isEmpty()){                 return false;             }else { char top = st.pop();                 if(ch==')'&&top!='('){                   ...

 Kadane's Algorithm implementation in java Code::  import java.util.*; class Test { public static void main(String[] args){ int[] arr =  {1,2,3,-2,5}; int maxSum = arr[0]; int currSum = 0; for(int i=0;i<arr.length;i++){ currSum += arr[i]; if(currSum > maxSum){ maxSum = currSum; } if(currSum<0){ currSum = 0; } } System.out.println(maxSum); } } o/p: 9 Largest Sum Contiguous Subarray Brute Force  Code:  import java.util.*; class Test { public static void main(String[] args){ int[] arr =  {1,2,3,-2,5}; int max = Integer.MIN_VALUE; for(int i=0;i<arr.length;i++){ int sum = arr[i]; max = Math.max(sum,max); for(int j=i+1;j<arr.length;j++){ sum = sum + arr[j]; max = Math.max(sum,max); } } System.out.println(max); } }

  Selection Sort Program in java Code: import java.util.*; import java.lang.*; import java.io.*; //selection Sort class Test { public static void main(String[] args){ int[] arr = {2,7,4,1,5,3}; for(int i=0;i<arr.length;i++){ int minVal = arr[i]; int ind = i; for(int j= i+1;j<arr.length;j++){ if(arr[j] < minVal){ ind = j; minVal = arr[j]; } } //swap with minimum  int temp = arr[i]; arr[i] = minVal; arr[ind] = temp; } for(int i : arr){ System.out.print(i+" "); } } }  Bubble Sort Program in java Code:: import java.util.*; import java.lang.*; import java.io.*; //Bubble Sort class Test { public static void main(String[] args){ int[] arr = {2,7,4,1,5,3}; for(int i=0;i<arr.length;i++){ //the last val is at its coorect Position for(int j=0;j<arr.length-i-1;j++){ if(arr[j]>arr[j+1]){ //swap int temp = arr[j]; arr[j] = arr[j+1]; arr[j+1] = temp...

 Quick Sort Program in java Code:: import java.util.*; import java.lang.*; import java.io.*; //Quick Sort class Test { public static void main(String[] args){ int[] arr = {8,7,3,4,11,13,14,2,17}; quickSort(arr,0,arr.length-1); for(int i : arr){ System.out.print(i+ " "); } } public static void quickSort(int[] arr,int s,int e){ if(s>=e){ return; } int pIndex = partition(arr,s,e); quickSort(arr,s,pIndex-1); quickSort(arr,pIndex+1,e); } public static int partition(int[] arr,int s,int e){ int pivot = arr[e]; int pIndex = s; for(int i=s;i<=e-1;i++){  if(arr[i] <= pivot){ int temp = arr[i]; arr[i] = arr[pIndex]; arr[pIndex] = temp; pIndex++; } } int temp = arr[e]; arr[e] = arr[pIndex]; arr[pIndex] = temp; return pIndex; } }

 insertion Sort Program in java Code: import java.util.*; import java.lang.*; import java.io.*; //Insertion Sort class Test{ public static void main(String[] args){ int[] arr = {7,2,4,1,5,3}; insertion(arr); for(int i : arr){ System.out.print(i+" "); } } public static void insertion(int[] arr){ for(int i=1;i<arr.length;i++){ int hole = i; int val = arr[i]; while(hole>0 && arr[hole-1]>val){ arr[hole] = arr[hole-1]; hole--; } arr[hole] = val; } } }

 Bubble Sort Program in java Code:: import java.util.*; import java.lang.*; import java.io.*; //Bubble Sort class Test{ public static void main(String[] args){ int[] arr = {2,7,4,1,5,3}; bubble(arr); for(int i : arr){ System.out.print(i+" "); } } public static void bubble(int[] arr){ for(int i=0;i<arr.length;i++){ //the last val is at its correct Position for(int j=0;j<arr.length-i-1;j++){ if(arr[j]>arr[j+1]){ //swap int temp = arr[j]; arr[j] = arr[j+1]; arr[j+1] = temp; } } } } } Optimized code if the right part of the array is sorted code: import java.util.*; import java.lang.*; import java.io.*; //Bubble Sort class Test{ public static void main(String[] args){ int[] arr = {2,7,4,1,5,3}; bubble(arr); for(int i : arr){ System.out.print(i+" "); } } public static void bubble(int[] arr){ for(int i=0;i<arr.length;i++){ int swap = 0; for(int j=0;j<...

 Selection Sort Program in java Code: import java.util.*; import java.lang.*; import java.io.*; class Test{ public static void main(String[] args){ int[] arr = {7,2,4,1,5,3}; selection(arr); for(int i : arr){ System.out.print(i+ " "); } } public static void selection(int[] arr){ for(int i=0;i<arr.length;i++){ int minVal = arr[i]; int ind = i; for(int j= i+1;j<arr.length;j++){ if(arr[j] < minVal){ ind = j; minVal = arr[j]; } } //swap with minimum  int temp = arr[i]; arr[i] = minVal; arr[ind] = temp; } } }

 binary to decimal conversion code: import java.util.*; import java.lang.*; import java.io.*; //binary to decimal class Test { public static void main(String[] args){ Scanner scn = new Scanner(System.in); //take the binary number from the user int bin = scn.nextInt(); //write the lgic to convert it into decimal int dec = 0; int i = 0;//digit place while(bin!=0){ //last digit int r = bin%10; //multiple remaider with 2 power digit place dec = dec +(r* (int)Math.pow(2,i)); //increment the position of i i++; //remove the last digit from the number bin = bin/10; } //print the decimal number System.out.println(dec); } } ex:: input : 1010 o/p: 10 input : 1000 o/p: 8 octal to decimal Conversion Code:: import java.util.*; import java.lang.*; import java.io.*; //binary to decimal class Test { public static void main(String[] args){ Scanner scn = new Scanner(System.in); //take the octal number from the user int oct =...

 hcf of the numbers Code:: import java.util.*; import java.lang.*; import java.io.*; //hcf of two numbers  //by efficient use of modulo operator in euclidean algorithm class Test { public static void main(String[] args){ int num1=36,num2=60,hcf; hcf = getHcf(num1,num2); System.out.println("the hcf : "+hcf); } public static int getHcf(int a,int b){ return b==0 ? a : getHcf(b,a%b); } } LCM of two numbers property  if we have 2 numbers num1,num2 and there lcm is l and hcf is h then num1 * num2 = l * h Code:: import java.util.*; import java.lang.*; import java.io.*; //lcm of two numbers  //by efficient use of modulo operator in euclidean algorithm class Test { public static void main(String[] args){ int num1=36,num2=60,hcf; hcf = getHcf(num1,num2); int lcm = (num1*num2)/hcf; System.out.println("the lcm: "+lcm); } public static int getHcf(int a,int b){ return b==0 ? a : getHcf(b,a%b); } }

 Merge Sort Program in java Code :: import java.util.*; import java.lang.*; import java.io.*; class Test { public static void main(String[] args){ int[] arr = {7,2,4,1,5,3}; mergeSort(arr); for(int i : arr){ System.out.print(i+" "); } } public static void mergeSort(int[] arr){ int n = arr.length; if(n<2){ return; } int mid = n/2; int[] left = new int[mid]; int[] right = new int[n-mid]; for(int i=0;i<mid;i++){ left[i] = arr[i]; } for(int i=mid;i<n;i++){ right[i-mid] = arr[i]; } mergeSort(left); mergeSort(right); merge(left,right,arr); } public static void merge(int[] left,int[] right,int[] arr){ int i = 0; int j = 0; int k = 0; while(i<left.length && j<right.length){ if(left[i]<right[j]){ arr[k] = left[i]; i++; }else{ arr[k] = right[j]; j++; } k++; } while(i!=left.length){ arr[k] = left[i]; i++; k++; } wh...

 Interacting With Multiple Databases in Hibernate For Explanation watch video :: Directory Structure: pom.xml <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>com.test</groupId> <artifactId>OracleMySQLHB</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>OracleMySQLHB</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.9</maven.compiler.source> <maven.compiler.target>1.9</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>j...

Component Mapping in Hibernate Using Annotations For explanation watch video:: Directory Structure pom.xml <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>com.test</groupId> <artifactId>ComponentMapping</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>ComponentMapping</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.9</maven.compiler.source> <maven.compiler.target>1.9</maven.compiler.target> </properties> <dependencies> <dependency> <groupId...