用递归处理 汉诺塔，迷宫和N皇后问题

汉诺塔

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 
 4 int hanoi(int dishs,int peg1,int peg2,int peg3)
 5 {
 6     if(dishs == 1)
 7         printf("盘子从 %d 移到 %d\n",peg1,peg3);
 8     else
 9     {
10         hanoi(dishs - 1,peg1,peg3,peg2);
11         printf("盘子从 %d 移到 %d\n",peg1,peg3);
12         hanoi(dishs - 1,peg2,peg1,peg3);
13     }
14 }
15 
16 int main()
17 {
18     hanoi(3,1,2,3);
19     return 0;
20 }
$gcc -o main *.c
$main
盘子从 1 移到 3
盘子从 1 移到 2
盘子从 3 移到 2
盘子从 1 移到 3
盘子从 2 移到 1
盘子从 2 移到 3
盘子从 1 移到 3

 迷宫

 1 //数字0：表示是可走的路径
 2 //数字1：表示是墙壁，不可走的路径
 3 //数字2：表示是走过的路径
 4 #include <stdio.h>
 5 
 6 int maze[7][10] = {
 7     1,1,1,1,1,1,1,1,1,1,
 8     1,0,1,0,1,0,0,0,0,1,
 9     1,0,1,0,1,0,1,1,0,1,
10     1,0,1,0,1,1,1,0,0,1,
11     1,0,1,0,0,0,0,0,1,1,
12     1,0,0,0,1,1,1,0,0,1,
13     1,1,1,1,1,1,1,1,1,1
14 };
15 
16 int find_path(int x,int y)
17 {
18     if(x == 1 && y == 1)
19     {
20         maze[x][y] = 2;
21         return 1;
22     }
23     else
24         if(maze[x][y] == 0)
25         {
26             maze[x][y] = 2;
27             if((find_path(x - 1,y) + 
28                 find_path(x + 1,y) +
29                 find_path(x,y - 1) +
30                 find_path(x,y + 1)) > 0)
31             return 1;
32             else
33             {
34                 maze[x][y] = 0;
35                 return 0;
36             }
37         }
38         else
39             return 0;
40 }
41 
42 int main()
43 {
44     int i,j;
45     
46     find_path(5,8);
47     printf("迷宫的路径如下图所示：\n");
48     for(i = 1;i < 6;i++)
49     {
50         for(j = 1;j < 9;j++)
51             printf("%d",maze[i][j]);
52         printf("\n");
53     }
54     return 0;
55 }
$gcc -o main *.c
$main
迷宫的路径如下图所示：
21010000
21010110
21011100
21222221
22211122

N皇后问题
  1 //数字1：表示是放置皇后
  2 //数字0：表示没有放置
  3 
  4 #include <stdio.h>
  5 #define MAXQUEEN 8
  6 
  7 int pad[MAXQUEEN][MAXQUEEN] = {
  8     0,0,0,0,0,0,0,0,
  9     0,0,0,0,0,0,0,0,
 10     0,0,0,0,0,0,0,0,
 11     0,0,0,0,0,0,0,0,
 12     0,0,0,0,0,0,0,0,
 13     0,0,0,0,0,0,0,0,
 14     0,0,0,0,0,0,0,0,
 15     0,0,0,0,0,0,0,0
 16 }; 
 17 
 18 int place(int x,int y);
 19 
 20 int put_queen(int x,int y,int times)
 21 {
 22     int i,j,result = 0;
 23     
 24     if(times > MAXQUEEN)
 25         return 1;
 26     else
 27         if(place(x,y))
 28         {
 29             pad[x][y] = 1;
 30             for(i = 0; i < MAXQUEEN; i++)
 31                 for(j = 0; j < MAXQUEEN; j++)
 32                 {
 33                     result += put_queen(i,j,times+1);
 34                     if(result > 0)
 35                         break;
 36                 }
 37             if(result > 0)
 38                 return 1;
 39             else
 40             {
 41                 pad[x][y] = 0;
 42                 return 0;
 43             }
 44         }
 45         else
 46             return 0;
 47 }
 48 
 49 int place(int x,int y)
 50 {
 51     int x1,y1;
 52     
 53     if(pad[x][y] != 0)
 54         return 0;
 55     x1 = x - 1;
 56     y1 = y - 1;
 57     while(x1 >= 0 && y1 >= 0)
 58         if(pad[x1--][y1--] != 0)
 59             return 0;
 60     x1 = x + 1;
 61     y1 = y + 1;
 62     while(x1 < MAXQUEEN && y1 < MAXQUEEN)
 63         if(pad[x1++][y1++] != 0)
 64             return 0;
 65     x1 = x + 1;
 66     y1 = y - 1;
 67     while(x1 < MAXQUEEN && y1 >= 0)
 68         if(pad[x1++][y1--] != 0)
 69             return 0;
 70     x1 = x - 1;
 71     y1 = y + 1;
 72     while(x1 >= 0 && y1 < MAXQUEEN)
 73         if(pad[x1--][y1++] != 0)
 74             return 0;
 75     x1 = x;
 76     y1 = y + 1;
 77     while(y1 < MAXQUEEN)
 78         if(pad[x1][y1++] != 0)
 79             return 0;
 80     x1 = x;
 81     y1 = y - 1;
 82     while(y1 >= 0)
 83         if(pad[x1][y1--] != 0)
 84             return 0;
 85     x1 = x + 1;
 86     y1 = y;
 87     while(x1 < MAXQUEEN)
 88         if(pad[x1++][y1] != 0)
 89             return 0;
 90     x1 = x - 1;
 91     y1 = y;
 92     while(x1 >= 0)
 93         if(pad[x1--][y1] != 0)
 94             return 0;
 95     return 1;
 96 }
 97 
 98 int main()
 99 {
100     int i,j;
101     
102     put_queen(0,0,1);
103     printf("放置八皇后的棋盘图形：\n");
104     for(i = 0; i < MAXQUEEN; i++)
105     {
106         for( j = 0; j < MAXQUEEN; j++)
107             printf("%d ",pad[i][j]);
108         printf("\n");
109     }
110     return 0;
111 }
$gcc -o main *.c
$main
放置八皇后的棋盘图形：
1 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 1 
0 0 0 0 0 1 0 0 
0 0 1 0 0 0 0 0 
0 0 0 0 0 0 1 0 
0 1 0 0 0 0 0 0 
0 0 0 1 0 0 0 0
posted @ 2020-12-28 01:22  互联星空  阅读(87)  评论(0)    收藏  举报