#include
typedef struct {
int row;
int col;
}Position;
int FindPath (Position start, Position finish, int &PathLen, Position *&path)
{ //计算从起始位置start到目标位置finish的最短布线路径，找到返回1，否则，返回0
int i;
if ((start.row = = finish.row) && (start.col = = finish.col)) {
PathLen = 0; return 0; } //start = finish
//设置方格阵列”围墙”
for (i = 0; i <= m+1; i++)
grid[0][i] = grid[n+1][i] = 1; //顶部和底部
for (i = 0; i <= n+1; i++)
grid[i][0] = grid[i][m+1] = 1; //左翼和右翼
//初始化相对位移
int NumOfNbrs = 4; //相邻方格数
Position offset[4], here, nbr;
offset[0].row = 0; offset[0].col = 1; //右
offset[0].row = 1; offset[0].col = 0; //下
offset[0].row = 0; offset[0].col = -1; //左
offset[0].row = -1; offset[0].row = 0; //上
here.row = start.row;
here.col = start.col;
LinkedQueue Q; //标记可达方格位置
do {
for (i = 0; i< NumOfNbrs; i++) { //标记可达相邻方格
nbr.row = here.row + offset[i].row ;
nbr.col = here.col + offset[i].col;
if (grid[nbr.row][nbr.col] = = 0) { //该方格未标记
grid[nbr.row][nbr.col] = grid[here.row][here.col] + 1;
if ((nbr.row = = finish.row) && (nbr.col = = finish.col)) break;//完成布线
Q.Add(nbr);
}
}
if ((nbr.row = = finishi.row) && (nbr.col = = finish.col)) break;//完成布线
if (Q.IsEmpty()) //活队列是否为空
return 0; //无解
Q.delete(here); //取下一个扩展结点
}while (1);
//构造最短布线路径
PathLen = grid[finish.row][finish.col] － 2;
path = new Position[PathLen];
here = finish;
for (int j = PathLen – 1; j >= 0; j--) { //找前驱位置
path[j] = here;
for (i = 0; i< NumOfNbrs; i++) {
nbr.row = here.row + offset[i].row ;
nbr.col = here.col + offset[i].col;
if (grid[nbr.row][nbr.col] = = j+2) break;
}
here = nbr; //向前移动
}
return 1;
}
void main ()
{
int grid[8][8];
int PathLen, *path;
Position start, finish;
start.row = 3; start.col = 2;
finish.row = 4; finish.col = 6;
FindPath (start, finish, PathLen, path);
}
