java数据结构基础:稀疏数组

//稀疏数组

public class SparseArray {

     public static void main(String[] args) {

         //创建一个原始的二维数组11 * 11

         int [][] chessArr = new int [ 11 ][ 11 ];

         chessArr[ 1 ][ 2 ] = 1 ;

         chessArr[ 2 ][ 3 ] = 2 ;

         chessArr[ 4 ][ 5 ] = 2 ;

         //输出原始的二维数组

         for ( int [] row : chessArr) {

             for ( int i : row) {

                 System.out.printf( "%d\t" , i);

             }

             System.out.println();

         }

         //二维数组转稀疏数组

         //首先遍历二维数组，得到非0数据的个数

         int sum = 0 ;

         for ( int i = 0 ; i < 11 ; i++) {

             for ( int j = 0 ; j < 11 ; j++) {

                 if (chessArr[i][j] != 0 ) {

                     sum++;

                 }

             }

         }

         //创建对应的稀疏数组

         int [][] sparseArr = new int [sum + 1 ][ 3 ];

         //对稀疏数组赋值

         sparseArr[ 0 ][ 0 ] = 11 ;

         sparseArr[ 0 ][ 1 ] = 11 ;

         sparseArr[ 0 ][ 2 ] = sum;

         //遍历二维数组，将非0的值存放到稀疏数组中

         int count = 0 ;  //用于记录是第几个非0数据

         for ( int i = 0 ; i < 11 ; i++) {

             for ( int j = 0 ; j < 11 ; j++) {

                 if (chessArr[i][j] != 0 ) {

                     count++;

                     sparseArr[count][ 0 ] = i;

                     sparseArr[count][ 1 ] = j;

                     sparseArr[count][ 2 ] = chessArr[i][j];

                 }

             }

         }

         //输出稀疏数组

         for ( int i = 0 ; i < sparseArr.length; i++) {

             System.out.printf( "%d\t%d\t%d\t" , sparseArr[i][ 0 ], sparseArr[i][ 1 ], sparseArr[i][ 2 ]);

             System.out.println();

         }

         //稀疏数组恢复二维数组

         //首先读取稀疏数组的第一行，根据第一行的数据，创建原始的二维数组

         int newChessArr[][] = new int [sparseArr[ 0 ][ 0 ]][sparseArr[ 0 ][ 1 ]];

         //读取稀疏数组后几行的数据，赋值给二维数组

         for ( int i = 1 ; i < sparseArr.length; i++) {

             newChessArr[sparseArr[i][ 0 ]][sparseArr[i][ 1 ]] = sparseArr[i][ 2 ];

         }

         //输出恢复后的二维数组

         //输出原始的二维数组

         for ( int [] row : newChessArr) {

             for ( int i : row) {

                 System.out.printf( "%d\t" , i);

             }

             System.out.println();

         }

     }

}