Add more BONUS problems

Author: MadhavBahl

BONUS/Arrays/AddAllElements/AddAllElements.java

@@ -0,0 +1,20 @@
+import java.util.*;
+
+class Play {
+    public static void main(String[] args) {
+        // Given array is stored in arr[][]
+        int[][] arr = {{1, 2, 3, 4}, {1, 2, 3}, {1, 2}, {1}};
+
+        int sum = 0;
+        System.out.println("The given 2D array is: ");
+        for (int[] row: arr) {
+            for (int element: row) {
+                System.out.print(element + " ");
+                sum += element;
+            }
+            System.out.println("");
+        }
+
+        System.out.println("The sum of elements is = " + sum);
+    }
+}

BONUS/Arrays/AddAllElements/README.md

@@ -0,0 +1,30 @@
+# Add All Elements
+
+WAP to add all the elements in the given 2D array
+
+## Solution
+
+### [Java Implementation](./AddAllElements.java)
+
+```java
+import java.util.*;
+
+class Play {
+    public static void main(String[] args) {
+        // Given array is stored in arr[][]
+        int[][] arr = {{1, 2, 3, 4}, {1, 2, 3}, {1, 2}, {1}};
+
+        int sum = 0;
+        System.out.println("The given 2D array is: ");
+        for (int[] row: arr) {
+            for (int element: row) {
+                System.out.print(element + " ");
+                sum += element;
+            }
+            System.out.println("");
+        }
+
+        System.out.println("The sum of elements is = " + sum);
+    }
+}
+```

BONUS/Arrays/CheckIdentity/CheckIdentity.java

@@ -0,0 +1,44 @@
+/**
+ * Check Identity Matrix
+ * @author MadhavBahlMD
+ * @date 26/01/2019
+ */
+
+import java.util.*;
+
+class CheckIdentity {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the N (for NxN matrix): ");
+        int n = input.nextInt();
+
+        // Input the array
+        int[][] arr = new int[n][n];
+        System.out.println("Enter the elements: ");
+        for (int i=0; i<n; i++) {
+            for (int j=0; j<n; j++) {
+                System.out.print("arr[" + i + "][" + j + "] = ");
+                arr[i][j] = input.nextInt();
+            }
+        }
+
+        // Check for identity
+        for (int i=0; i<n; i++) {
+            for (int j=0; j<n; j++) {
+                if (i == j) {
+                    if (arr[i][j] != 1) {
+                        System.out.println("Given matrix is not identity!");
+                        System.exit(0);
+                    }
+                } else {
+                    if (arr[i][j] != 0) {
+                        System.out.println("Given matrix is not identity!");
+                        System.exit(0);
+                    }
+                }
+            }
+        }
+
+        System.out.println("Given matrix is an identity matrix!");
+    }
+}

BONUS/Arrays/CheckIdentity/README.md

@@ -0,0 +1,54 @@
+# Check Identity Matrix
+
+WAP to find whether the given NxN matix is an identity matrix
+
+## Solution
+
+### [Java Implementation](./CheckIdentity.java)
+
+```java
+/**
+ * Check Identity Matrix
+ * @author MadhavBahlMD
+ * @date 26/01/2019
+ */
+
+import java.util.*;
+
+class CheckIdentity {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the N (for NxN matrix): ");
+        int n = input.nextInt();
+
+        // Input the array
+        int[][] arr = new int[n][n];
+        System.out.println("Enter the elements: ");
+        for (int i=0; i<n; i++) {
+            for (int j=0; j<n; j++) {
+                System.out.print("arr[" + i + "][" + j + "] = ");
+                arr[i][j] = input.nextInt();
+            }
+        }
+
+        // Check for identity
+        for (int i=0; i<n; i++) {
+            for (int j=0; j<n; j++) {
+                if (i == j) {
+                    if (arr[i][j] != 1) {
+                        System.out.println("Given matrix is not identity!");
+                        System.exit(0);
+                    }
+                } else {
+                    if (arr[i][j] != 0) {
+                        System.out.println("Given matrix is not identity!");
+                        System.exit(0);
+                    }
+                }
+            }
+        }
+
+        System.out.println("Given matrix is an identity matrix!");
+    }
+}
+```

BONUS/Arrays/LinearSearch/LinearSearch.java

@@ -0,0 +1,30 @@
+import java.util.*;
+
+class LinearSearch {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the number of elements in array: ");
+        int size = input.nextInt();
+
+        System.out.println("Enter the array elements: ");
+        int[] arr = new int[size];
+        for (int i=0; i<size; i++) {
+            System.out.print("arr[" + i + "] = ");
+            arr[i] = input.nextInt();
+        }
+
+        System.out.print("Enter the number to search: ");
+        int n = input.nextInt();
+        Boolean found = false; int pos=-1;
+
+        for (int i=0; i<size; i++)
+            if (arr[i] == n) {
+                pos = i;
+                found = true;
+                break;
+            }
+
+        if (found)  System.out.println("The given number, " + n + " exists in the array at index: " + pos);
+        else  System.out.println("The given number, " + n + " does not exist in the array");
+    }
+}

BONUS/Arrays/LinearSearch/README.md

@@ -0,0 +1,40 @@
+# Linear Search
+
+WAP to perform linear search on the given array
+
+## Solution
+
+### [Java Implementation](./LinearSearch.java)
+
+```java
+import java.util.*;
+
+class LinearSearch {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the number of elements in array: ");
+        int size = input.nextInt();
+
+        System.out.println("Enter the array elements: ");
+        int[] arr = new int[size];
+        for (int i=0; i<size; i++) {
+            System.out.print("arr[" + i + "] = ");
+            arr[i] = input.nextInt();
+        }
+
+        System.out.print("Enter the number to search: ");
+        int n = input.nextInt();
+        Boolean found = false; int pos=-1;
+
+        for (int i=0; i<size; i++)
+            if (arr[i] == n) {
+                pos = i;
+                found = true;
+                break;
+            }
+
+        if (found)  System.out.println("The given number, " + n + " exists in the array at index: " + pos);
+        else  System.out.println("The given number, " + n + " does not exist in the array");
+    }
+}
+```

BONUS/Arrays/MatrixSum/MatrixSum.java

@@ -0,0 +1,64 @@
+/**
+ * Print Matrix Sum
+ */
+
+import java.util.*;
+
+class MatrixSum {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the number of rows: ");
+        int row = input.nextInt();
+        System.out.print("Enter the number of columns: ");
+        int col = input.nextInt();
+
+        // Input the 1st Matrix
+        int[][] arr1 = new int[row][col];
+        System.out.println("Enter the elements of first matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print("arr1[" + i + "][" + j + "] = ");
+                arr1[i][j] = input.nextInt();
+            }
+        }
+
+        // Input the 2nd Matrix
+        int[][] arr2 = new int[row][col];
+        System.out.println("Enter the elements of second matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print("arr2[" + i + "][" + j + "] = ");
+                arr2[i][j] = input.nextInt();
+            }
+        }
+
+        // Print 1st matrix
+        System.out.println("First Matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print(arr1[i][j] + " ");
+            }
+            System.out.println("");
+        }
+
+        // Print 2nd matrix
+        System.out.println("Second Matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print(arr2[i][j] + " ");
+            }
+            System.out.println("");
+        }
+
+        // Print Transpose matrix
+        int[][] sum = new int[row][col];
+        System.out.println("Sum of input matrices: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                sum[i][j] = arr1[i][j] + arr2[i][j];
+                System.out.print(sum[i][j] + " ");
+            }
+            System.out.println("");
+        }
+    }
+}

BONUS/Arrays/MatrixSum/README.md

@@ -0,0 +1,74 @@
+# Matrix Sum
+
+WAP to add 2 matrices
+
+## Solution
+
+### [Java Implementation](./MatrixSum.java)
+
+```java
+/**
+ * Print Matrix Sum
+ */
+
+import java.util.*;
+
+class MatrixSum {
+    public static void main(String[] args) {
+        Scanner input = new Scanner (System.in);
+        System.out.print("Enter the number of rows: ");
+        int row = input.nextInt();
+        System.out.print("Enter the number of columns: ");
+        int col = input.nextInt();
+
+        // Input the 1st Matrix
+        int[][] arr1 = new int[row][col];
+        System.out.println("Enter the elements of first matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print("arr1[" + i + "][" + j + "] = ");
+                arr1[i][j] = input.nextInt();
+            }
+        }
+
+        // Input the 2nd Matrix
+        int[][] arr2 = new int[row][col];
+        System.out.println("Enter the elements of second matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print("arr2[" + i + "][" + j + "] = ");
+                arr2[i][j] = input.nextInt();
+            }
+        }
+
+        // Print 1st matrix
+        System.out.println("First Matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print(arr1[i][j] + " ");
+            }
+            System.out.println("");
+        }
+
+        // Print 2nd matrix
+        System.out.println("Second Matrix: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                System.out.print(arr2[i][j] + " ");
+            }
+            System.out.println("");
+        }
+
+        // Print Transpose matrix
+        int[][] sum = new int[row][col];
+        System.out.println("Sum of input matrices: ");
+        for (int i=0; i<row; i++) {
+            for (int j=0; j<col; j++) {
+                sum[i][j] = arr1[i][j] + arr2[i][j];
+                System.out.print(sum[i][j] + " ");
+            }
+            System.out.println("");
+        }
+    }
+}
+```

BONUS/Arrays/README.md

@@ -4,4 +4,10 @@ Some more problems on arrays!
 
 ## Questions
 
-1. [WAP to reverse the given arary](./Reverse/)
+1. [WAP to reverse the given arary](./Reverse/)
+2. [WAP to perform linear search on the given array](./LinearSearch/)
+3. [WAP to find whether the given NxN matix is an identity matrix](./CheckIdentity/)
+4. [WAP to print the transpose of the given matrix](./Transpose/)
+5. [WAP to add 2 matrices](./MatrixSum/)
+6. [WAP to add all the elements in the given 2D array](./AddAllElements/)
+7. [WAP to read a sentence and display the sentence with reversed words](./ReverseWords/)