稀疏数组
- 当数组中大部分元素为0,或者为同一值的数组时,可以使用稀疏数组来保存该数组
- 稀疏数组的处理方式:
- 记录数组一共有几行几列,有多少个不同值
- 把具有不同值的元素和行列及值记录在一个小规模的数组中,从而缩小程序的规模

package array;
public class arrayDemo08 {
public static void main(String[] args) {
int[][] array1 = new int[11][11];
array1[1][2] = 1;
array1[2][3] = 2;
System.out.println("输出原始的数组:");
for (int[] ints : array1) {
for (int anInt : ints) {
System.out.print(anInt + "\t");
}
System.out.println();
}
System.out.println("========================================================");
int s = 0;
for (int i = 0; i < array1.length; i++) {
for (int j = 0; j < array1[i].length; j++) {
if (array1[i][j] != 0) {
s++;
}
}
}
System.out.println("有效值的个数为:" + s);
System.out.println("========================================================");
int[][] array2 = new int[s + 1][3];
array2[0][0] = 11;
array2[0][1] = 11;
array2[0][2] = s;
int count = 0;
for (int i = 0; i < array1.length; i++) {
for (int j = 0; j < array1[i].length; j++) {
if (array1[i][j] != 0){
count++;
array2[count][0]=i;
array2[count][1]=j;
array2[count][2]=array1[i][j];
}
}
}
System.out.println("输出稀疏数组:");
for (int i = 0; i<array2.length;i++){
System.out.println(array2[i][0]+"\t"
+array2[i][1]+"\t"
+array2[i][2]+"\t");
}
System.out.println("========================================================");
System.out.println("将稀疏数组还原:");
int[][] array3 = new int[array2[0][0]][array2[0][1]];
for (int i = 1; i < array2.length; i++) {
array3[array2[i][0]][array2[i][1]]=array2[i][2];
}
for (int[] ints : array3) {
for (int anInt : ints) {
System.out.print(anInt + "\t");
}
System.out.println();
}
}
}
