I am neo java week 5

 

Skill builder

1. Raja was arranging gift boxes in his store.

import java.util.*; import java.lang.*; import java.io.*; class Main { public static void main(String[] a) throws Exception { Scanner input = new Scanner(System. in); int N = input. nextInt(); if (N <= 0) return; int array[][] = new int[N][]; for (int ctr = 0; ctr < N; ctr++) { array[ctr] = new int[ctr + 1]; } int val = 1; for (int ctr_row = 0; ctr_row < N; ctr_row++) { for (int ctr_col = 0; ctr_col < ctr_row + 1; ctr_col++) { array[ctr_row][ctr_col] = val++; } } for (int ctr = 0; ctr < N; ctr++) { System.out.println(Arrays.toString(array[ctr])); } } }

2. Write a program to print the matrix in a zig_zag form.

import java.util.Scanner; class Main { static void printZigZag(int row, int col, int a[][]) { int evenRow = 0; int oddRow = 1; while (evenRow < row) { for (int i = 0; i < col; i++) { System.out.print(a[evenRow][i] + " "); } evenRow = evenRow + 2; if(oddRow < row) { for (int i = col - 1; i >= 0; i--) { System.out.print(a[oddRow][i] + " "); } } oddRow = oddRow + 2; } } public static void main(String[] args) { int r, c; int i,j; Scanner in=new Scanner(System.in); r=in.nextInt(); c=in.nextInt(); int mat[][]=new int[10][10]; for(i=0;i<r;i++){ for(j=0;j<c;j++){ mat[i][j]=in.nextInt(); } } printZigZag(r , c , mat); }}

3. Write a program to obtain a matrix and find the sum of each row and each column.

import java.util.Scanner; class matrix { static void row_sum(int arr[][],int m, int n) { int i, j, sum = 0; for (i = 0; i < m; ++i) { for (j = 0; j < n; ++j) { sum = sum + arr[i][j]; } System.out.println("Sum of the row " + i + " = " + sum); sum = 0; } } static void column_sum(int arr[][], int m,int n) { int i, j, sum = 0; for (i = 0; i < m; ++i) { for (j = 0; j < n; ++j) { sum = sum + arr[j][i]; } System.out.println("Sum of the column " + i + " = " + sum); sum = 0; } } public static void main(String[] args) { int i, j,m,n; Scanner sc = new Scanner(System.in); m = sc.nextInt(); n = sc.nextInt(); int[][] arr = new int[m][n]; for (i = 0; i < m; i++) for (j = 0; j < n; j++) arr[i][j] = sc.nextInt(); row_sum(arr,m,n); column_sum(arr,m,n); }}

4. Johnsy wants to create a matrix in which the elements are formed differently.

import java.util.*; import java.lang.*; import java.io.*; class Q01Simple2DArray { public static void main (String[] args) throws java.lang.Exception { Scanner input = new Scanner(System. in); int N = input. nextInt(); if (N <= 0) return; int M = input. nextInt(); if (M <= 0) return; int numbers[][] = new int[N][M]; for (int ctr_row = 0; ctr_row < N; ctr_row++) { for (int ctr_col = 0; ctr_col < M; ctr_col++) { numbers[ctr_row][ctr_col] = ctr_row + ctr_col; } } for (int ctr_row = 0; ctr_row < N; ctr_row++) { for (int ctr_col = 0; ctr_col < M; ctr_col++) { System.out.print(numbers[ctr_row][ctr_col] + "\t"); } System.out.println(); } } }

5. Write a program to implement matrix multiplication.

import java.io.*; import java.util.*; class Main { public static void main(String [] args) { int n,i,j,k; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int mat1[][] = new int[n][n]; int mat2[][] = new int[n][n]; int m[][] = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { mat1[i][j] = sc.nextInt(); } } for(i=0;i<n;i++) { for(j=0;j<n;j++) { mat2[i][j] = sc.nextInt(); } } for(i=0;i<n;i++) { for(j=0;j<n;j++) { m[i][j] =0; for(k=0;k<n;k++) { m[i][j] += mat1[i][k]*mat2[k][j]; } } } for(i=0;i<n;i++) { for(k=0;k<n;k++) { System.out.print(m[i][k]+" "); } System.out.println(); } } }

6. Lucarnos Film Festival is an annual film festival and is also known for being a prestigious platform for art house films

import java.io.*; import java.util.*; class collisionsOfEvents { public static void main(String [] args) { int n,m,i,j,k=0,c=0; Scanner sc = new Scanner(System.in); n = sc.nextInt(); m = sc.nextInt(); int a[][] = new int[n][m]; for(i=0;i<n;i++) { for(j=0;j<m;j++) { a[i][j] = sc.nextInt(); } } for(i=0;i<m;i++) { for(j=0;j<n;j++) { if(a[j][i]==1){c++;} } if(c>2){k=k+((c-1)*(c)/2);} else if(c==2){k++;} c=0; } System.out.println(k); }}

7. The Pan Am 73 flight from Bombay to New York en route Karachi and Frankfurt was hijacked by a few Palestinian terrorists at the Karachi International Airport.

import java.io.*; import java.util.*; class MidAged { public static void main(String [] args) { int i,j,n,count=0; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int a[][] = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { a[i][j] = sc.nextInt(); } } for(i=0;i<n;i++) { for(j=0;j<n;j++) { if(i==j) { if(a[i][j] >=18 && a[i][j] <=60) { count++; } } } } System.out.println(count); } }

8. Write a program to obtain a matrix and find the sum of its diagonal elements.

Note: Only square matrix. import java.util.Scanner; class disgonalSum { public static void main(String args[]) { Scanner sc = new Scanner(System.in); int i,j,row,col,sum=0; row = sc.nextInt(); col = sc.nextInt(); int[][] mat = new int[row][col]; for(i=0;i<row;i++) { for(j=0;j<col;j++) { mat[i][j] = sc.nextInt(); } } for(i=0;i<row;i++) { for(j=0;j<col;j++) { if(i==j) { sum = sum + mat[i][j]; } } } System.out.println(sum) ; } }

9. Write a program to obtain a matrix and find the sum of the elements in the lower triangular matrix..

import java.util.Scanner; class matrix { static void sum(int mat[][], int r, int c) { int i, j; int lower_sum = 0; for (i = 0; i < r; i++) for (j = 0; j < c; j++) { if (j <= i) { lower_sum += mat[i][j]; } } System.out.print(lower_sum); } public static void main (String[] args) { int r,c,i,j; Scanner sc = new Scanner(System.in); r = sc.nextInt(); c = sc.nextInt(); int [][] mat = new int[r][c]; for(i=0;i<r;i++) { for(j=0;j<c;j++) { mat[i][j] = sc.nextInt(); } } sum(mat, r, c); } }

10. Write a program to find the normal of a matrix.

import java.util.Scanner; class normal { static int MAX = 100; static int findNormal(int mat[][], int n) { int sum = 0; for (int i=0; i<n; i++) for (int j=0; j<n; j++) sum += mat[i][j]*mat[i][j]; return (int)Math.sqrt(sum); } public static void main (String[] args) { int i,j,n; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int [][] mat = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { mat[i][j] = sc.nextInt(); } } System.out.println (findNormal(mat, n)); }}

Challange yourelf

1. Nurikabe logical game (sometimes called Islands in the Stream) is a binary determination puzzle. Write a program to find the number of white cells in the final configuration of the board, given a valid initial configuration.

import java.io.*; import java.util.*; class numberofWhiteCells { public static void main(String [] args) { int i,j,n,count=0; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int a[][] = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { a[i][j] = sc.nextInt(); if(a[i][j] < 11) { count += a[i][j]; } } } System.out.println(count); } }

2. Nurikabe logical game (sometimes called Islands in the Stream) is a binary determination puzzle. The step 1 of solving the puzzle is identifying "Full islands". Below figure is the one after identifying full islands.

import java.io.*; import java.util.*; class identifyNeighborNumbers { public static void main(String [] args) { int i,j,n; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int a[][] = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { a[i][j] = sc.nextInt(); } } for(i=0;i<n;i++) { for(j=0;j<n;j++) { if((a[i][j]<11)&&(a[i][j]>0)) { if((i<n-2)&&(a[i+2][j]<11)&&(a[i+2][j]>0)){a[i+1][j]=0;}//vertical if((j<n-2)&&(a[i][j+2]<11)&&(a[i][j+2]>0)){a[i][j+1]=0;}//horizontal if((i>0)&&(j>0)&&(a[i-1][j-1]<11)&&(a[i-1][j-1]>0)){a[i-1][j]=a[i][j-1]=0;}//decreasing slope if((i<n-1)&&(j>0)&&(a[i+1][j-1]<11)&&(a[i+1][j-1]>0)){a[i+1][j]=a[i][j-1]=0;}//increasing slope } } } for(i=0;i<n;i++) { for(j=0;j<n;j++) { System.out.print(a[i][j]+" "); } System.out.println(); } } }

3. Winter is back and is end of season’s sale all over.

import java.io.*; import java.util.*; class robotAtTheFair { public static void main(String [] args) { int r,c,i,j,x,y,n,m,s=0,dir=1,direction=1; Scanner sc = new Scanner(System.in); r = sc.nextInt(); c = sc.nextInt(); char gnd[][] = new char[r][c]; for(i=0;i<r;i++) { for(j=0;j<c;j++) { gnd[i][j] = sc.next().charAt(0); } } x = sc.nextInt(); y = sc.nextInt(); n = sc.nextInt(); char path[] = new char[n]; path = sc.next().toCharArray(); for(direction=1;direction<5;direction++) { dir=direction; i=x;j=y; for(m=0;m<n;m++) { if(dir==1) //North { switch(path[m]) { case 'F':if(i>0){i--;}else{s=-1;};break; case 'L':dir=4;break; case 'R':dir=2;break; } } else if(dir==2) //East { switch(path[m]) { case('F'):if(j<c-1) { j++; } else { s=-1; break; } case('L'):dir=1;break; case('R'):dir=3;break; } } else if(dir==4) //West { switch(path[m]) { case('F'):if(j>0) { j--; } else { s=-1; break; } case('L'):dir=3;break; case('R'):dir=1;break; } } else if(dir==3) //South { switch(path[m]) { case('F'):if(i<r-1) { i++; } else { s = -1; break; } case('L'):dir=2;break; case('R'):dir=4;break; } } if((gnd[i][j]=='X')||(s==-1)){s=-1;break;} } if(s==0){gnd[i][j]='o';} s=0; } for(i=0;i<r;i++) { for(j=0;j<c;j++) { if(gnd[i][j]=='o') { System.out.print(i+" "); System.out.print(j); System.out.println(); } } } } }

4. Nurikabe logical game (sometimes called Islands in the Stream) is a binary determination puzzle. Write a program to find the count of numbered cells, given a valid initial board configuration.

import java.io.*; import java.util.*; class countOfNumberedCells { public static void main(String [] args) { int i,j,n,count=0; Scanner sc = new Scanner(System.in); n = sc.nextInt(); int a[][] = new int[n][n]; for(i=0;i<n;i++) { for(j=0;j<n;j++) { a[i][j] = sc.nextInt(); if(a[i][j] < 11) { count++; } } } System.out.println(count); } }

5. Write a program to obtain a matrix and find the sum of the elements in the upper triangular matrix

import java.util.Scanner; class matrix { static void sum(int mat[][], int r, int c) { int i, j; int upper_sum = 0; for (i = 0; i < r; i++) for (j = 0; j < c; j++) { if (i <= j) { upper_sum += mat[i][j]; } } System.out.println(upper_sum); } public static void main (String[] args) { int r,c,i,j; Scanner sc = new Scanner(System.in); r = sc.nextInt(); c = sc.nextInt(); int [][] mat = new int[r][c]; for(i=0;i<r;i++) { for(j=0;j<c;j++) { mat[i][j] = sc.nextInt(); } } sum(mat, r, c); } }