文章目录
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- 练习1:遍历二维数组int a[][] = {{23.65,43,68},{45,99,86,80},{76,81,34,45},{88,64,48,25}}后,再通过循环计算该二维数组的两条对角线之和。
- 练习2:一个3×3的网格,将从1到9的数字放入方格,达到能够使得每行每列以及每个对角线的值相加都相同。
- 练习3:交换二维数组 int array[][] = {{8,75,23},{21,534},{15,23,20 }};的行、列数据。
- 练习4:使用二维数组实现杨辉三角算法。
练习1:遍历二维数组int a[][] = {{23.65,43,68},{45,99,86,80},{76,81,34,45},{88,64,48,25}}后,再通过循环计算该二维数组的两条对角线之和。
public class GetSum {
public static void main(String args[]) {
int a[][] = {{ 23, 65, 43, 68 },
{ 45, 99, 86, 80 },
{ 76, 81, 34, 45 },
{ 88, 64, 48, 25 }};
System.out.println("原始数组如下:");
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a[i].length; j++) {
System.out.print(a[i][j] + " ");
}
System.out.println();
}
int sum1 = 0;
int sum2 = 0;
for (int i = 0, j = a[i].length - 1; i < a.length; i++, j--) {
sum1 += a[i][i];
sum2 += a[i][j];
}
System.out.println("对角线总和为:" + (sum1 + sum2));
}
}
练习2:一个3×3的网格,将从1到9的数字放入方格,达到能够使得每行每列以及每个对角线的值相加都相同。
public class NineGrids {
public static void main(String[] args) {
int arr[][] = new int[3][3];
int a = 2;
int b = 3 / 2;
for (int i = 1; i <= 9; i++) {
arr[a++][b++] = i;
if (i % 3 == 0) {
a = a - 2;
b = b - 1;
} else {
a = a % 3;
b = b % 3;
}
}
System.out.println("九宫格:");
for (int i = 0; i < 3; i++) {
for (int j = 0; j < arr.length; j++) {
System.out.print(arr[i][j] + " ");
}
System.out.println();
}
}
}
练习3:交换二维数组 int array[][] = {{8,75,23},{21,534},{15,23,20 }};的行、列数据。
public class SwapRC {
public static void main(String[] args) {
int i, j;
int[][] array = { { 8, 75, 23 }, { 21, 55, 34 }, { 15, 23, 20 } };
System.out.println("—————原始数组—————");
for (i = 0; i < 3; i++) {
for (j = 0; j < 3; j++) {
System.out.print(array[i][j] + "\t");
}
System.out.println();
}
int temp;
for (i = 0; i < 3; i++) {
for (j = 0; j < i; j++) {
temp = array[i][j];
array[i][j] = array[j][i];
array[j][i] = temp;
}
}
System.out.println("——调换位置之后的数组——");
for (i = 0; i < 3; i++) {
for (j = 0; j < 3; j++) {
System.out.print(array[i][j] + "\t");
}
System.out.println();
}
}
}
练习4:使用二维数组实现杨辉三角算法。
public class YangHui {
public static void main(String[] args) {
int[][] Array_int = new int[10][];
for (int i = 0; i < Array_int.length; i++) {
Array_int[i] = new int[i + 1];
for (int j = 0; j < Array_int[i].length; j++) {
if (i <= 1) {
Array_int[i][j] = 1;
continue;
} else {
if (j == 0 | j == Array_int[i].length - 1)
Array_int[i][j] = 1;
else
Array_int[i][j] = Array_int[i - 1][j - 1] + Array_int[i - 1][j];
}
}
}
for (int i = 0; i < Array_int.length; i++) {
for (int j = 0; j < Array_int[i].length; j++)
System.out.print(Array_int[i][j] + "\t");
System.out.println();
}
}
}