mirror of https://github.com/evanferrao/dsa
61 lines
2.2 KiB
Java
61 lines
2.2 KiB
Java
// write a program to generate a n * n matrix in spiral order given user input n and the elements of the matrix
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import java.util.Scanner;
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class SpiralMatrixGeneration{
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public static void main(String[] args){
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Scanner sc = new Scanner(System.in);
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System.out.println("Enter the number of rows and columns of the matrix");
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int rows = sc.nextInt();
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int cols = sc.nextInt();
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int length = rows*cols;
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int[][] matrix = new int[rows][cols];
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int lengthArray[] = new int[length];
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System.out.println("Enter the elements of the matrix");
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for(int i=0;i<length;i++){
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lengthArray[i] = sc.nextInt();
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}
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System.out.println("The elements of the matrix in spiral order are:");
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spiralOrder(matrix,rows, cols, lengthArray);
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for(int i=0;i<rows;i++){
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for(int j=0;j<cols;j++){
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System.out.print(matrix[i][j]+" ");
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}
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System.out.println();
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}
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sc.close();
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}
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public static void spiralOrder(int[][] matrix, int rows, int cols, int lengthArray[]){
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int top = 0;
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int bottom = rows-1;
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int left = 0;
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int right = cols-1;
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int length_index = 0;
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while(top<=bottom && left<=right){
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// this loop does not need to check for the condition top<=bottom and left<=right as
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for(int i=left;i<=right;i++){
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matrix[top][i] = lengthArray[length_index++];
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}
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top++;
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// this loop does not need to check for the condition top<=bottom and left<=right as it is already checked in the while loop
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for(int i=top;i<=bottom;i++){
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matrix[i][right] = lengthArray[length_index++];
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}
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right--;
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if(top<=bottom){
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for(int i=right;i>=left;i--){
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matrix[bottom][i] = lengthArray[length_index++];
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}
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bottom--;
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}
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if(left<=right){
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for(int i=bottom;i>=top;i--){
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matrix[i][left] = lengthArray[length_index++];
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}
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left++;
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}
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}
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}
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} |