/**
 * @author 興趣使然黃小黃
 * @version 1.0
 * 二維數(shù)組轉稀疏數(shù)組、稀疏數(shù)組還原二維數(shù)組的實現(xiàn)
 */
public class SparseArray {

    public static void main(String[] args) {
        //先創(chuàng)建原始二維數(shù)組
        int[][] originalArray = new int[10][10];
        originalArray[0][4] = 1;
        originalArray[0][8] = 1;
        originalArray[1][5] = 1;
        originalArray[1][7] = 1;
        originalArray[4][8] = 1;
        originalArray[5][5] = 1;
        originalArray[7][2] = 1;
        originalArray[8][7] = 1;
        //輸出原始的二維數(shù)組
        System.out.println("原始的二維數(shù)組:");
        for (int[] row: originalArray) {
            for (int data : row) {
                System.out.printf("%d\t", data);
            }
            System.out.println();
        }

        //將二維數(shù)組轉成稀疏數(shù)組
        //1.遍歷二維數(shù)組，得到非0的有效數(shù)據(jù)的個數(shù)
        int amount = 0;
        for (int i = 0; i < originalArray.length; i++) {
            for (int j = 0; j < originalArray[i].length; j++) {
                if (originalArray[i][j] != 0){
                    amount++;
                }
            }
        }
        System.out.println("amount = " + amount);
        //2.創(chuàng)建對應的稀疏數(shù)組 sparseArray[amount+1][3], 并初始化稀疏數(shù)組第一行的數(shù)據(jù)
        //第一行第一列: 原數(shù)組的行數(shù)   第一行第二列: 原數(shù)組的列數(shù)  第一行第三列: 原數(shù)組的有效數(shù)據(jù)個數(shù)
        int[][] sparseArray = new int[amount + 1][3];
        sparseArray[0][0] = 10;
        sparseArray[0][1] = 10;
        sparseArray[0][2] = amount;
        //3.遍歷二維數(shù)組,將非0值存儲進稀疏數(shù)組
        int count = 0; //用于記錄是第幾個非零數(shù)據(jù)
        for (int i = 0; i < originalArray.length; i++) {
            for (int j = 0; j < originalArray[i].length; j++) {
                if (originalArray[i][j] != 0){
                    count++;
                    sparseArray[count][0] = i; //記錄所在行
                    sparseArray[count][1] = j; //記錄所在列
                    sparseArray[count][2] = originalArray[i][j]; //記錄值
                }
            }
        }
        //輸出稀疏數(shù)組
        System.out.println("稀疏數(shù)組:");
        for (int i = 0; i < sparseArray.length; i++) {
                System.out.printf("%d\t%d\t%d\n", sparseArray[i][0], sparseArray[i][1], sparseArray[i][2]);
        }

        //將稀疏數(shù)組恢復成為二維數(shù)組
        //1.根據(jù)稀疏數(shù)組的第一行初始化二維數(shù)組
        int[][] recoveredArray = new int[sparseArray[0][0]][sparseArray[0][1]];
        //2.讀取稀疏數(shù)組的后面行數(shù)據(jù)，賦值給原始二維數(shù)組
        for (int i = 1; i < sparseArray.length; i++) {
            recoveredArray[sparseArray[i][0]][sparseArray[i][1]] = sparseArray[i][2];
        }
        //輸出二維數(shù)組
        System.out.println("恢復后的二維數(shù)組:");
        for (int[] row: recoveredArray) {
            for (int data : row) {
                System.out.printf("%d\t", data);
            }
            System.out.println();
        }
    }
}