2D-ArrayProblem-1

Q1 - Given two integer matrices, multiply the matrices, if possible, else return “Invalid Input”. (Medium)
Assignment Solutions

Input1:

Expected Output:
n1 = 2
m1 = 3
arr1 = {{2,4,1}, {3,,6}}
n2 = 3
m2 = 2
arr2 = {{1,2}, {3,4}, {,7}}

19 27
48 68

import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println("Enter the dimensions of first array: ");
int n1 = scn.nextInt();
int m1 = scn.nextInt();
int[][] arr1 = new int[n1][m1];
System.out.println("Enter the elements of first array: ");
for (int i = 0; i < n1; i++) {
for (int j = 0; j < m1; j++) {
arr1[i][j] = scn.nextInt();
}
}
System.out.println("Enter the dimensions of second array: ");
int n2 = scn.nextInt();
int m2 = scn.nextInt();
int[][] arr2 = new int[n2][m2];
System.out.println("Enter the elements of second array: ");
for (int i = 0; i < n2; i++) {
for (int j = 0; j < m2; j++) {

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arr2[i][j] = scn.nextInt();
}
}
if (m1 != n2) {
return;
}
int[][] ans = new int[n1][m2];
for (int i = 0; i < n1; i++) {
for (int j = 0; j < m2; j++) {
for (int k = 0; k < m1; k++) {
ans[i][j] += (arr1[i][k] * arr2[k][j]);
}
}
}
for (int i = 0; i < n1; i++) {
for (int j = 0; j < m2; j++) {
System.out.print(ans[i][j] + " ");
}
System.out.println();
}
}
}


import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println("Enter the dimensions of the array: ");
int n = scn.nextInt();
int m = scn.nextInt();
int[][] mat = new int[n][m];
System.out.println("Enter the elements of the array: ");
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
mat[i][j] = scn.nextInt();
}
}
for (int x = 0; x < n / 2; x++) {
for (int y = x; y < n - x - 1; y++) {
int temp = mat[x][y];
Assignment Solutions

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mat[x][y] = mat[y][n - 1 - x];
mat[y][n - 1 - x] = mat[n - 1 - x][n - 1 - y];
mat[n - 1 - x][n - 1 - y] = mat[n - 1 - y][x];
mat[n - 1 - y][x] = temp;
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
System.out.print(mat[i][j] + " ");
}
System.out.println();
}
}
}



import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println("Enter the dimensions of the array: ");
int n = scn.nextInt();
int m = scn.nextInt();
int[][] mat = new int[n][m];
System.out.println("Enter the elements of the array: ");
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
mat[i][j] = scn.nextInt();
}
}
for (int i = 1; i < n; i++) {
for (int j = 1; j < m; j++) {
if(mat[i][j] != mat[i-1][j-1]){
System.out.println(false);
return;
}
}
}
System.out.println(true);
}
}


import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println(]Enter the dimensions of the array: ]);
int n = scn.nextInt();
int m = scn.nextInt();
int[][] mat = new int[n][m];
System.out.println(]Enter the elements of the array: ]);
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
mat[i][j] = scn.nextInt();
}
}
int[] arr = new int[n*m];
int idx = 0;
int row = 0;
int col = 0;
while(col < m){
int i = row;
int j = col;
while(i >= 0 && j < m){
arr[idx] = mat[i][j];
idx++;
i--;
j++;
}
row++;
if(row >= n){
row = n-1;
col++;
}
}
for(int i = 0; i < arr.length; i++){
System.out.print(arr[i] + ] ]);
}
}
}


import java.util.Scanner;
import java.util.Arrays;
public class Test {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println("Enter the dimensions of the array: ");
int n = scn.nextInt();
int m = scn.nextInt();
int[][] mat = new int[n][m];
System.out.println("Enter the elements of the array: ");
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
mat[i][j] = scn.nextInt();
}
}
Arrays.sort(mat, (a,b) -> a[0]-b[0]);
int count = 0;
int i = 0;
while(i < n){
while(i < n-1 && mat[i+1][0] <= mat[i][1]){
mat[i+1][0] = mat[i][0];
mat[i+1][1] = Math.max(mat[i][1], mat[i+1][1]);
i++;
}
i++;
count++;
}
System.out.println(count);
}
}