数字在for循环中发出

Question

我正在制作一个用地形表示来读取栅栏的程序。现在，代码查看数组，并报告需要多少栅栏，每边1 2.5米。问题是我不知道这些数字出了什么问题。它很好地显示角值，但是边值是不正确的，除了最后一列显示正确的值，但这可能只是巧合。我有i's和j's来表示x和y值，到目前为止，这是我所有的代码。

package assignment_2;

public class Fencing {

    public static void main(String[] args) {
        boolean b = true;
        double corner = 0;
        double core = 0;
        double side = 0;
        int i = 0;
        int j = 0;
        int[][] map = { 
            { 0, 1, 1, 0 }, 
            { 1, 1, 1, 1 }, 
            { 1, 1, 1, 1 }, 
            { 1, 1, 0, 1 } 
        };
        for (i = 0; i < 4; i++) {
            for (j = 0; j < 4; j++) {
                if (map[i][j] != 1 && map[i][j] != 0) {
                    b = false;
                    System.out.println("--> A value of " + map[i][j] + " was found at " + i + "," + j);
                }
            }
        }
        if (b == false && i == 4) {
            System.out.println("The map is invalid");
            return;
        } else {
            System.out.println("Map is valid");
        }
        if (map[0][0] == 1) {
            corner += 5;
            if (map[1][0] == 1 && map[0][1] == 1) {
                corner += 0;
            }
            if (map[1][0] != 1 && map[0][1] != 1) {
                corner += 5;
            }
            if (map[1][0] != 1 && map[0][1] == 1 || map[1][0] == 1 && map[0][1] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[0][3] == 1) {
            corner += 5;
            if (map[1][3] == 1 && map[0][2] == 1) {
                corner += 0;
            }
            if (map[1][3] != 1 && map[0][2] != 1) {
                corner += 5;
            }
            if (map[1][3] != 1 && map[0][2] == 1 || map[1][3] == 1 && map[0][2] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[3][0] == 1) {
            corner += 5;
            if (map[3][1] == 1 && map[2][0] == 1) {
                corner += 0;
            }
            if (map[3][1] != 1 && map[02][0] != 1) {
                corner += 5;
            }
            if (map[3][1] != 1 && map[2][0] == 1 || map[3][1] == 1 && map[2][0] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[3][3] == 1) {
            corner += 5;
            if (map[3][2] == 1 && map[2][3] == 1) {
                corner += 0;
            }
            if (map[3][2] != 1 && map[2][3] != 1) {
                corner += 5;
            }
            if (map[3][2] != 1 && map[2][3] == 1 || map[3][2] == 1 && map[2][3] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        System.out.println("Corner fencing = " + corner);
        for (i = 1; i > 2; i++) { // Top
            if (map[0][j] == 1) {
                side += 2.5;
                if (map[i + 1][0] == 1 && map[i - 1][0] == 1) {
                    side += 0;
                }
                if (map[i + 1][0] != 1 || map[i - 1][0] != 1) {
                    side += 2.5;
                }
                if (map[i + 1][0] != 1 && map[i - 1][0] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the first row, fencing = " + side);
        for (i = 1; i > 2; i++) { // Bottom
            if (map[i][3] == 1) {
                side += 2.5;
                if (map[i + 1][3] == 1 && map[i - 1][3] == 1) {
                    side += 0;
                }
                if (map[i + 1][3] != 1 || map[i - 1][3] != 1) {
                    side += 2.5;
                }
                if (map[i + 1][3] != 1 && map[i - 1][3] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the bottom row, fencing = " + side);
        for (j = 1; j < 3; j++) {// Right
            if (map[3][j] == 1) {
                side += 2.5;
                if (map[3][j + 1] == 1 && map[3][j - 1] == 1) {
                    side += 0;
                }
                if (map[3][j + 1] != 1 || map[3][j - 1] != 1) {
                    side += 2.5;
                }
                if (map[3][j + 1] != 1 && map[3][j - 1] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the first column, fencing = " + side);
        for (j = 1; j < 3; j++) {// Left
            if (map[0][j] == 1) {
                side += 2.5;
                if (map[0][j + 1] == 1 && map[0][j - 1] == 1) {
                    side += 0;
                }
                if (map[0][j + 1] != 1 || map[0][j - 1] != 1) {
                    side += 2.5;
                }
                if (map[0][j + 1] != 1 && map[0][j - 1] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the last column, fencing = " + side);
    }
}

弯角工作正常，但问题是边角( for循环)。边沿穿过数组的当前行，如果数字为1，则检查它们旁边的数字，如果为0，则添加2.5m。这个问题似乎与i和j使值不正确有关，但我不太确定它们有什么问题。有人能帮我吗？

以下是当前的输出：

Corner fencing = 12.5

After the first row, fencing = 0.0

After the bottom row, fencing = 0.0

After the first column, fencing = 5.0

After the last column, fencing = 15.0

这是预期的产出：

Corner fencing = 12.5

After the first row, fencing = 5.0

After the bottom row, fencing = 10.0

After the first column, fencing = 15.0

After the last column, fencing = 20.0

Answer 1

我不完全理解代码中的栅栏是什么，或者边角代表什么，但我将指出您的代码存在的几个问题，以及可能出错的地方。

1-共享局部变量：

int i,j;在多个块之间共享，因此在一个块中更改这些块肯定会影响它们在另一个块中的状态。

Sol:如果vars要具有相同的名称，则->使用命名块

2-错误条件：代码中有两个错误的条件-bottom和top for循环-

(i = 1; i > 2; i++)

这里是修改后的代码：

public class Fencing {

    public static void main(String[] args) {
        boolean b = true;
        double corner = 0;
        double core = 0;
        double side = 0;

        int[][] map = { 
            { 0, 1, 1, 0 }, 
            { 1, 1, 1, 1 }, 
            { 1, 1, 1, 1 }, 
            { 1, 1, 0, 1 } 
        };

        firstBlock:{
            int i = 0;
            int j = 0;
            for (i = 0; i < 4; i++) {
            for (j = 0; j < 4; j++) {
                if (map[i][j] != 1 && map[i][j] != 0) {
                    b = false;
                    System.out.println("--> A value of " + map[i][j] + " was found at " + i + "," + j);
                }
            }
        }
        if (b == false && i == 4) {
            System.out.println("The map is invalid");
            return;
        } else {
            System.out.println("Map is valid");
        }
        if (map[0][0] == 1) {
            corner += 5;
            if (map[1][0] == 1 && map[0][1] == 1) {
                corner += 0;
            }
            if (map[1][0] != 1 && map[0][1] != 1) {
                corner += 5;
            }
            if (map[1][0] != 1 && map[0][1] == 1 || map[1][0] == 1 && map[0][1] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[0][3] == 1) {
            corner += 5;
            if (map[1][3] == 1 && map[0][2] == 1) {
                corner += 0;
            }
            if (map[1][3] != 1 && map[0][2] != 1) {
                corner += 5;
            }
            if (map[1][3] != 1 && map[0][2] == 1 || map[1][3] == 1 && map[0][2] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[3][0] == 1) {
            corner += 5;
            if (map[3][1] == 1 && map[2][0] == 1) {
                corner += 0;
            }
            if (map[3][1] != 1 && map[02][0] != 1) {
                corner += 5;
            }
            if (map[3][1] != 1 && map[2][0] == 1 || map[3][1] == 1 && map[2][0] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        if (map[3][3] == 1) {
            corner += 5;
            if (map[3][2] == 1 && map[2][3] == 1) {
                corner += 0;
            }
            if (map[3][2] != 1 && map[2][3] != 1) {
                corner += 5;
            }
            if (map[3][2] != 1 && map[2][3] == 1 || map[3][2] == 1 && map[2][3] != 1) {
                corner += 2.5;
            }
        } else {
            corner += 0;
        }
        System.out.println("Corner fencing = " + corner);
        }
       secondBlock:{ 
            int i = 0;
            int j = 0;
            for (i = 1; i < 2; i++) { // Top
            if (map[0][j] == 1) {
                side += 2.5;
                if (map[i + 1][0] == 1 && map[i - 1][0] == 1) {
                    side += 0;
                }
                if (map[i + 1][0] != 1 || map[i - 1][0] != 1) {
                    side += 2.5;
                }
                if (map[i + 1][0] != 1 && map[i - 1][0] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the first row, fencing = " + side);}
        thirdBlock:{
            int i = 0;
            int j = 0;
            for (i = 1; i < 2; i++) { // Bottom
            if (map[i][3] == 1) {
                side += 2.5;
                if (map[i + 1][3] == 1 && map[i - 1][3] == 1) {
                    side += 0;
                }
                if (map[i + 1][3] != 1 || map[i - 1][3] != 1) {
                    side += 2.5;
                }
                if (map[i + 1][3] != 1 && map[i - 1][3] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the bottom row, fencing = " + side);}
        fourthBlock:{
            int i = 0;
            int j = 0;
        for (j = 1; j < 3; j++) {// Right
            if (map[3][j] == 1) {
                side += 2.5;
                if (map[3][j + 1] == 1 && map[3][j - 1] == 1) {
                    side += 0;
                }
                if (map[3][j + 1] != 1 || map[3][j - 1] != 1) {
                    side += 2.5;
                }
                if (map[3][j + 1] != 1 && map[3][j - 1] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the first column, fencing = " + side);}
        lastBlock:{
            int i = 0;
            int j = 0;
        for (j = 1; j < 3; j++) {// Left
            if (map[0][j] == 1) {
                side += 2.5;
                if (map[0][j + 1] == 1 && map[0][j - 1] == 1) {
                    side += 0;
                }
                if (map[0][j + 1] != 1 || map[0][j - 1] != 1) {
                    side += 2.5;
                }
                if (map[0][j + 1] != 1 && map[0][j - 1] != 1) {
                    side += 5;
                }
            } else {
                side += 0;
            }
        }
        System.out.println("After the last column, fencing = " + side);}
    }
}

产出如下：

Map is valid
Corner fencing = 12.5
After the first row, fencing = 0.0
After the bottom row, fencing = 5.0
After the first column, fencing = 10.0
After the last column, fencing = 20.0

我必须指出，first row fencing is equal to 0.0而不是5，这是因为(map[i + 1][0] != 1 && map[i - 1][0] != 1)，所以您必须相应地改变这一点。

Answer 2

我将假设您想要计算每个元素的所有外部面，即数组中的1，每个面构成一个重为2.5m的栅栏。

这并不是说它很漂亮，但它基本上应该能做你想做的事情：

public class Fencing {

public static void main(String[] args) {

  double totalFencingUnits = 0;
  double fencingUnitWeight = 2.5;

    boolean b = true;
    double corner = 0;
    double core = 0;
    double side = 0;
    int i = 0;
    int j = 0;
    int[][] map = { 
        { 0, 1, 1, 0 }, 
        { 1, 1, 1, 1 }, 
        { 1, 1, 1, 1 }, 
        { 1, 1, 0, 1 } 
    };


  for (i = 0; i < map.length; i++) {
        for (j = 0; j < map[0].length; j++) {

            if (map[i][j] != 1 && map[i][j] != 0) {
                b = false;
                System.out.println("--> An invalid value of " + map[i][j] + " was found at " + i + "," + j);
            }

          if ( map[i][j] == 1){

            //do the outer corners
            if((i == 0 && (j == 0 || j == map.length - 1)) || (i == map.length - 1 && (j == 0 || j == map.length - 1))){
              System.out.println("A corner " + map[i][j] + " was found at " + i + "," + j);
              totalFencingUnits += 2;
              switch (2*i - j  ) {
                case -3:  
                  totalFencingUnits += map[i][j - 1] > 0?0:1;
                  totalFencingUnits += map[i + 1][j] > 0?0:1;
                 break;
                case 6:  
                 totalFencingUnits += map[i - 1][j] > 0?0:1;
                 totalFencingUnits += map[i ][j + 1] > 0?0:1;
                 break;
                case 0:  
                 totalFencingUnits += map[i][j + 1] > 0?0:1;
                 totalFencingUnits += map[i +1 ][j] > 0?0:1;
                 break;
                case 3:  
                 totalFencingUnits += map[i - 1][j] > 0?0:1;
                 totalFencingUnits += map[i ][j - 1] > 0?0:1;
                 break;
                default:
                break;
              }
            }
            //do the outer sides
            else if((i == 0 && (j != 0 && j != map.length - 1)) || (i == map.length - 1 && (j != 0 && j != map.length - 1))
              || (j == 0  && (i != 0 && i != map.length - 1)) || (j == map.length - 1 && (i != 0 && i != map.length - 1))){
              System.out.println("A side " + map[i][j] + " was found at " + i + "," + j);
              totalFencingUnits ++;
              if ( i == 0){
                totalFencingUnits += map[i][j - 1] > 0?0:1;
                 totalFencingUnits += map[i + 1][j] > 0?0:1;
                totalFencingUnits += map[i][j +  1] > 0?0:1;
              }
              if (i == map.length - 1){
                totalFencingUnits += map[i][j - 1] > 0?0:1;
                 totalFencingUnits += map[i -1 ][j] > 0?0:1;
                totalFencingUnits += map[i][j +  1] > 0?0:1;
              }
              if ( j == 0){
                totalFencingUnits += map[i - 1][j] > 0?0:1;
                 totalFencingUnits += map[i][j + 1] > 0?0:1;
                totalFencingUnits += map[i + 1][j ] > 0?0:1;
              }
              if ( j == map.length - 1){
                totalFencingUnits += map[i - 1][j] > 0?0:1;
                 totalFencingUnits += map[i][j - 1] > 0?0:1;
                totalFencingUnits += map[i + 1][j ] > 0?0:1;
              }

            }
            //now do the internals blocks
            else {

              System.out.println("An internal " + map[i][j] + " was found at " + i + "," + j);
              totalFencingUnits += map[i - 1][j] > 0?0:1;
                 totalFencingUnits += map[i][j - 1] > 0?0:1;
                totalFencingUnits += map[i ][j + 1] > 0?0:1;
              totalFencingUnits += map[i + 1][j ] > 0?0:1;

            }

          }
        }
    }

    if (b == false && i == 4) {
        System.out.println("The map is invalid");
        return;
    } else {
        System.out.println("Map is valid");
        System.out.println("TOTAL FENCING UNITS: " + totalFencingUnits );
        System.out.println("TOTAL FENCING WEIGHT: " + totalFencingUnits * fencingUnitWeight);
    }



    }
}

我在编译做了这个

得到了这个输出：

地图有效

在0,1处发现侧1

在0,2处发现侧1

在1,0处发现侧1

在1,1处发现一个内部1

在1,2处发现一个内部1

在1,3处发现了侧1

在2,0发现了一侧1

在2,1发现了一个内部1

在2,2处发现了一个内部1

发现侧1在2,3处

在3,0发现了一个拐角处

发现侧1在3,1

在3,3处发现了一个拐角处

击剑单位总数: 18.0

击剑总重量: 45.0

而且，看起来我的输入的输出实际上应该是45 (即。18张脸)。你应该也考虑一下外面的边缘吗？