Question

我在Java中有一个二维数组。值如下：

我想现在将所有“2”更改为1，但只有那些与其他人接壤的人。所以在说“改变（4 | 4）到”2“之后，我想让我的数组像这样：

这样做的最快方法是什么？

Answer 1

假设你使用二维数组：

have int x and y set to 0
start from [x][y] on the array
Step 1: Check to if number equals "2"
  If it does and:
  0<x<4 and 0<y<4: Check [x-1][y-1],[x][y-1],[x][y+1],[x-1][y],[x+1][y], and [x+1][y+1]
  x=0 and 0<y<3: Check [x][y-1],[x][y+1],[x+1][y], and [x+1][y+1]
  x=4 and 0<y<3: Check [x-1][y-1],[x][y-1],[x][y+1],[x-1][y]
  0<x<4 and y=0: Check [x][y+1],[x-1][y],[x+1][y], and [x+1][y+1]
  0<x<4 and y=3: Check [x-1][y-1],[x][y-1],[x-1][y],[x+1][y]
  and so on....
check to see if [x][y] = any of the checks
   if so: store a 1 in [x][y] in an alternative array of the same size (lets call it flags)
iterate and repeat from step 1 until you have gone through the entire array
run through the flags and if the value is 1 at any address [x][y] change the corresponding value in our original array to "1".

抱歉，这有点罗嗦，也许令人困惑，如果我需要澄清，请告诉我。

Answer 2

到目前为止，您的代码在哪里？

您可以尝试使用嵌套的for循环，然后将if-else语句放在内部循环中
1。将查看索引左侧和右侧的值
2。如果它在2（并且是2）的旁边，将在索引中交换/分配2与a 1，否则它将不管它。

您是否希望将其设置为可扩展，以便它可以与0s，1s和2s的任何数组一起使用，或者只提供您提供的确切数组？

如果您需要任何说明并包含您的代码，请告知我们，以便我们能够解决问题。

Answer 3

此示例使用2D数组作为数组数组。

它生成带有随机数的二维数组：
- array [] []是源数组，所有替换例程都将在被替换的[] []数组中执行（这是源代码的副本）。
- SIZE_I - 行数和SIZE_J - 列数;
- RANGE_FROM - 数组中的最小数字和RANGE_TO - 最大数字;
- 搜索 - 要搜索的号码;
- REPLACE - 要替换的号码。
- 数量 - 数量或找到和替换的项目。
它将源数组打印到屏幕;
它检查源数组是否匹配SEARCH常量与数组项目数组[i] [j]。根据项目的位置，应该满足几个条件来替换被替换的[] []数组中的这个项目，并将数量变量增加一个。
它将已更换的数组打印到屏幕和已替换项目的数量。

我相信你可以通过将2D数组用作一个数组来获得性能。例如，您的2D数组可以表示为{2,1,0,2,1,1,0,2,2,2,1,1,1,2,2,0,0,0,2,2}但是你应该妥善处理它。

public static void main(String[] args) {
final int RANGE_FROM = 0;
final int RANGE_TO = 2;
final int SEARCH = 2;
final int REPLACE_TO = 1;
final int SIZE_I = 4;
final int SIZE_J = 5;
int quantity = 0;
int array[][] = new int[SIZE_I][SIZE_J];
int replaced[][] = new int[SIZE_I][SIZE_J];

// Generate arrays
for (int i = 0; i < SIZE_I; i++) {
    for (int j = 0; j < SIZE_J; j++) {
    array[i][j] = (int) (RANGE_FROM + Math.random() * (RANGE_TO - RANGE_FROM + 1));
    replaced[i][j] = array[i][j];
    }
}

// Display array
System.out.println("Source array:");
for (int x[]: array) {
    for (int y: x) {
    System.out.print(y + " ");
    }
    System.out.println();
}
System.out.println();

// Check array
for (int i = 0; i < array.length; i++) {
    for (int j = 0; j < array[i].length; j++) {
    if (i == 0 && j == 0) {
        if (array[i][j] == SEARCH && (array[i+1][j] == SEARCH || array[i][j+1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i == 0 && j == array[i].length - 1) {
        if (array[i][j] == SEARCH && (array[i+1][j] == SEARCH || array[i][j-1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i == array.length -1 && j == 0) {
        if (array[i][j] == SEARCH && (array[i-1][j] == SEARCH || array[i][j+1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i == array.length -1 && j == array[i].length - 1) {
        if (array[i][j] == SEARCH && (array[i][j-1] == SEARCH || array[i-1][j] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i == 0 && j != 0 && j != array[i].length - 1) {
        if (array[i][j] == SEARCH && (array[i][j-1] == SEARCH || array[i+1][j] == SEARCH || array[i][j+1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i != 0 && i != array.length - 1 && j == array[i].length - 1) {
        if (array[i][j] == SEARCH && (array[i][j-1] == SEARCH || array[i-1][j] == SEARCH || array[i+1][j] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i == array.length - 1 && j != 0 && j != array[i].length - 1) {
        if (array[i][j] == SEARCH && (array[i][j-1] == SEARCH || array[i-1][j] == SEARCH || array[i][j+1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else if (i != 0 && i != array.length - 1 && j == 0) {
        if (array[i][j] == SEARCH && (array[i-1][j] == SEARCH || array[i][j+1] == SEARCH || array[i+1][j] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    else {
        if (array[i][j] == SEARCH && (array[i-1][j] == SEARCH || array[i][j+1] == SEARCH || array[i+1][j] == SEARCH || array[i][j-1] == SEARCH)) {
        quantity++;
        replaced[i][j] = REPLACE_TO;
        }
    }
    }       
}

// Display replaced array
System.out.println("Replaced array:");
for (int x[]: replaced) {
    for (int y: x) {
    System.out.print(y + " ");
    }
    System.out.println();
}
System.out.println();
System.out.println("Replace quantity: " + quantity);
System.out.println();
}

在二维Java-Array中搜索和标记

3 个答案: