我有一个由零和一组组成的矩形数组。我需要获得一个由一个索引组成的路径。我需要获得最好的一条,即在起点上可以相互连接的数量最长的最佳路径。路径是一组可以相互连接的路径:垂直,水平或对角线,您可以使用所有这些方向移动。
答案 0 :(得分:1)
您可以使用简单的递归算法遍历整个数组。对于每次调用该函数,您都会获得一个已访问过的单元格列表("路径")以及您刚刚输入的当前单元格。
您可以将当前单元格添加到列表中,并查看您所处的任何" 1"不在您的路径列表中的单元格。
如果你没有" 1"您周围的单元格不在路径列表中,返回路径列表。
如果你有" 1"您尚未访问的周围的单元格,使用您到目前为止的路径递归地对每个单元格使用函数,按长度比较它们的返回结果路径,并返回最长路径。
添加了代码示例:
using System;
using System.IO;
using System.Text;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;
using AUV_Topology;
using System.Collections.Generic;
using System.Media;
using System.Linq;
namespace AUVtopology
{
public partial class Form1 : Form
{
static int[,] array;
static List<int[]> path;
//This method is used to make sure the coordinate array
//is contained in the list. List.contains(new int[] {val1,val2}) was not enough.
static Boolean containsArray(List<int[]> list, int[] array)
{
if (array == null || array.Length == 0)
{
return false;
}
foreach (var listArray in list)
{
if (listArray != null && listArray.Length == array.Length)
{
for (int i = 0; i < listArray.Length; i++)
{
if (array[i] != listArray[i])
{
continue;
}
return true;
}
return false;
}
}
return false;
}
//This is the recursive method of the algorithm. It finds the
//maximum path of 1 cells in a matrix of 0/1 cells
static List<int[]> getMaxPath(int[,] array, List<int[]> maxPath, int rowIndex, int colIndex)
{
//End case in which we started (or ended up) in a 0 cell
if (array[rowIndex,colIndex] != 1) {
return maxPath;
}
//if we back-tracked and this cell was visited
if (containsArray(maxPath, new int[]{rowIndex,colIndex})) {
return maxPath;
}
//Add the current cell to the path.
maxPath.Add(new int[]{rowIndex,colIndex});
//Get the array limits.
int rowLength = array.GetLength(0);
int colLength = array.GetLength(1);
//If the path contains all the cells in the matrix, stop
if (maxPath.Count >= rowLength * colLength) {
return maxPath;
}
//remove one from lengths to make it the maximum index
colLength = colLength - 1;
rowLength = rowLength - 1;
//We'll use this variables to see which of the
//potential 7 paths is the longest.
List<int[]> futurePath;
//Go over all 8 possible adjoining cells:
//If we can go one down, one right
if (colIndex < colLength && rowIndex < rowLength) {
//We use maxPath first, since this is the first
//direction and by default is the longest
maxPath = getMaxPath (array, maxPath, rowIndex+1, colIndex+1);
}
//If we can go one down
if (colIndex < colLength) {
//We use futurePath now, since this is a second
//direction and a potential contender
futurePath = getMaxPath (array, maxPath, rowIndex, colIndex+1);
//We only need the maximum path.
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one down and one left
if (rowIndex>0 && colIndex < colLength) {
futurePath = getMaxPath (array, maxPath, rowIndex-1, colIndex+1);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one left
if (rowIndex>0) {
futurePath = getMaxPath (array, maxPath, rowIndex-1, colIndex);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one left and one up
if (rowIndex>0 && colIndex>0) {
futurePath = getMaxPath (array, maxPath, rowIndex-1, colIndex-1);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one up
if (colIndex>0) {
futurePath = getMaxPath (array, maxPath, rowIndex, colIndex-1);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one up and one right
if (colIndex>0 && rowIndex < rowLength) {
futurePath = getMaxPath (array, maxPath, rowIndex+1, colIndex-1);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//If we can go one right
if (rowIndex < rowLength) {
futurePath = getMaxPath (array, maxPath, rowIndex+1, colIndex);
if (futurePath.Count > maxPath.Count) {
maxPath = futurePath;
}
}
//We return the max path. Note: If none of the directions around
//us was applicable, we simply return the path we started
//with with our cell included.
return maxPath;
}