Aaa

java/matrix/Identity.java

@@ -0,0 +1,44 @@
+public class IdentityMatrix     
+{    
+    public static void main(String[] args) {    
+        int rows, cols;    
+        boolean flag = true;    
+
+        //Initialize matrix a    
+        int a[][] = {       
+                        {1, 0, 0},    
+                        {0, 1, 0},    
+                        {0, 0, 1}    
+                    };    
+
+        //Calculates the number of rows and columns present in the given matrix    
+
+          rows = a.length;    
+        cols = a[0].length;    
+
+        //Checks whether given matrix is a square matrix or not    
+        if(rows != cols){    
+            System.out.println("Matrix should be a square matrix");    
+        }    
+        else {    
+            //Checks if diagonal elements are equal to 1 and rest of elements are 0    
+            for(int i = 0; i < rows; i++){    
+                for(int j = 0; j < cols; j++){    
+                  if(i == j && a[i][j] != 1){    
+                      flag = false;    
+                      break;    
+                  }    
+                  if(i != j && a[i][j] != 0){    
+                      flag = false;    
+                      break;    
+                  }    
+                }    
+            }    
+
+            if(flag)    
+                System.out.println("Given matrix is an identity matrix");    
+            else    
+                System.out.println("Given matrix is not an identity matrix");    
+        }    
+    }    
+}    

java/matrix/MatrixAddition.java

@@ -0,0 +1,18 @@
+public class MatrixAdditionExample{  
+public static void main(String args[]){  
+//creating two matrices    
+int a[][]={{1,3,4},{2,4,3},{3,4,5}};    
+int b[][]={{1,3,4},{2,4,3},{1,2,4}};    
+
+//creating another matrix to store the sum of two matrices    
+int c[][]=new int[3][3];  //3 rows and 3 columns  
+
+//adding and printing addition of 2 matrices    
+for(int i=0;i<3;i++){    
+for(int j=0;j<3;j++){    
+c[i][j]=a[i][j]+b[i][j];    //use - for subtraction  
+System.out.print(c[i][j]+" ");    
+}    
+System.out.println();//new line    
+}    
+}}  

java/matrix/matrixSub.java

@@ -0,0 +1,18 @@
+public class MatrixSubExample{  
+public static void main(String args[]){  
+//creating two matrices    
+int a[][]={{1,3,4},{2,4,3},{3,4,5}};    
+int b[][]={{1,3,4},{2,4,3},{1,2,4}};    
+
+//creating another matrix to store the difference of two matrices    
+int c[][]=new int[3][3];  //3 rows and 3 columns  
+
+//Subtracting and printing addition of 2 matrices    
+for(int i=0;i<3;i++){    
+for(int j=0;j<3;j++){    
+c[i][j]=a[i][j]-b[i][j];    //use - for subtraction  
+System.out.print(c[i][j]+" ");    
+}    
+System.out.println();//new line    
+}    
+}}  

java/matrix/spiral.java

@@ -0,0 +1,102 @@
+public class SpiralPatternExample1  
+{  
+//defining method to print the spiral pattern or matrix  
+static void printSpiralPattern(int size)  
+{  
+//create two variables row and col to traverse rows and columns  
+int row = 0, col = 0;  
+int boundary = size - 1;  
+int sizeLeft = size - 1;  
+int flag = 1;  
+//variables r, l, u and d are used to determine the movement  
+// r = right, l = left, d = down, u = upper  
+char move = 'r';  
+//creating a 2D array for matrix  
+int[][] matrix =new int [size][size];  
+for (int i = 1; i < size * size + 1; i++)  
+{  
+    //assigning values  
+    matrix[row][col] = i;  
+//switch-case to determine the next index  
+switch (move)  
+{  
+//if right, go right  
+case 'r':  
+    col += 1;  
+    break;  
+//if left, go left  
+case 'l':  
+    col -= 1;  
+    break;  
+//if up, go up  
+case 'u':  
+    row -= 1;  
+    break;  
+//if down, go down  
+case 'd':  
+    row += 1;  
+    break;  
+}  
+//checks if the matrix has reached the array boundary  
+if (i == boundary)  
+    {  
+        //adds the left size for the next boundary  
+        boundary = boundary + sizeLeft;  
+        //decrease the size left by 1, if 2 rotations have been made  
+        if (flag != 2)  
+        {  
+        flag = 2;  
+        }  
+        else  
+        {  
+        flag = 1;  
+        sizeLeft -= 1;  
+        }  
+        //switch-case to rotate the movement  
+        switch (move)  
+        {  
+        //if right, rotate to down  
+        case 'r':  
+            move = 'd';  
+            break;  
+        // if down, rotate to left  
+        case 'd':  
+            move = 'l';  
+            break;  
+        // if left, rotate to up  
+        case 'l':  
+            move = 'u';  
+            break;  
+        // if up, rotate to right  
+        case 'u':  
+            move = 'r';  
+            break;  
+        }  
+    }  
+    }  
+//printing the spiral matrix or pattern  
+//outer for loop for rows  
+    for (row = 0; row < size; row++)  
+    {  
+        //inner for loop for columns  
+        for (col = 0; col < size; col++)  
+            {  
+                int n = matrix[row][col];  
+                if(n < 10)  
+                    System.out.print(n +" ");  
+                else  
+                    System.out.print(n +" ");  
+            }  
+        System.out.println();  
+    }  
+}  
+//driver Code  
+public static void main(String args[])  
+{  
+//size of the array?s row and column  
+int size = 5;  
+System.out.println("Spiral Matrix or Pattern is: \n");  
+//calling the method that prints the spiral pattern or matrix   
+printSpiralPattern(size);  
+}  
+}  

java/matrix/spiral2.java

@@ -0,0 +1,32 @@
+import java.util.Scanner;  
+import java.lang.Math;  
+public class SpiralPatternExample2  
+{  
+//function to print the spiral pattern  
+public static void printPattern(int n)  
+{  
+//detrmines the boundary size of the array  
+int size = 2 * n - 1;  
+//inner loop  
+for(int i = 1; i <= size; i++)  
+{  
+//outer loop      
+for(int j = 1; j <= size; j++)  
+{  
+//calculates and prints the values for pattern  
+System.out.print(Math.max(Math.abs(i - n), Math.abs(j - n)) + 1 + " ");  
+}  
+System.out.println();  
+}  
+}  
+//driver code  
+public static void main(String args[])  
+{  
+Scanner sc = new Scanner(System.in);  
+System.out.print("Enter the value of n: ");  
+int n = sc.nextInt();  
+System.out.println();  
+//function calling  
+printPattern(n);  
+}  
+}  

java/sorting/matrixSort.java

@@ -0,0 +1,36 @@
+import java.util.*;
+
+public class Main {
+	public static void main(String[] args)
+	{
+		// Initialize the 2D vector with some values
+		List<List<Integer> > v
+			= new ArrayList<>(Arrays.asList(
+				new ArrayList<>(Arrays.asList(5, 4, 7)),
+				new ArrayList<>(Arrays.asList(1, 3, 8)),
+				new ArrayList<>(Arrays.asList(2, 9, 6))));
+
+		int n = v.size();
+		List<Integer> x = new ArrayList<>();
+		for (int i = 0; i < n; i++) {
+			for (int j = 0; j < n; j++) {
+				x.add(v.get(i).get(j));
+			}
+		}
+		Collections.sort(x);
+		int k = 0;
+		for (int i = 0; i < n; i++) {
+			for (int j = 0; j < n; j++) {
+				v.get(i).set(j, x.get(k++));
+			}
+		}
+
+		System.out.println("Sorted Matrix Will be:");
+		for (List<Integer> row : v) {
+			for (int num : row) {
+				System.out.print(num + " ");
+			}
+			System.out.println();
+		}
+	}
+}