练习16

1. /***********************************************************************************
2. 16. 设有８枚硬币ａ，ｂ，ｃ，ｄ，ｅ，ｆ，ｇ，ｈ，其中有一枚硬币是伪造的。
3.  真伪硬币的区别仅是重量不同，可能重，可能轻。今要求以天平为工具，用最少的
4.  比较次数挑出伪造硬币，并鉴定它是重还是轻。
6.   方案: (1)  a,b,c VS d,e,f
7.         (2)  a,g,h VS d,b,c
8. ***********************************************************************************/
10. #include <stdio.h>
11. #include <stdlib.h>
12. #include <time.h>
14. enum{a=0,b,c,d,e,f,g,h};
16. //硬币数量
17. #define N   8
18. //标准硬币的重量
19. #define WEIGHT 10
20. //保存硬币的重量
21. int weight[N];
23. void main()
24. {
25.     int i;
26.     int LW,RW;// 天平左右边的重量
27.     for(i=0; i<N; i++)
28.         weight[i] = 10;
30.     //随即选择一枚硬币,改变其重量
31.     {
32.         int s;
33.         srand(time(NULL));
34.         s = rand()%N;
35.         weight[s] += rand()%2*2-1;
36.     }
38.     //-------------------------------------
39.     //输出随机数据
40.     for(i=0; i<N; i++)
41.     {
42.         printf("%3d",weight[i]);
43.     }
44.     printf("/n");
45.     //-------------------------------------
47.     LW = weight[a] + weight[b] + weight[c];
48.     RW = weight[d] + weight[e] + weight[f];
49.     if(LW == RW)//a,g质量不同
50.     {
51.         LW = weight[a];
52.         RW = weight[g];
53.         if(LW == RW)
54.         {
55.             RW = weight[h];
56.             if(LW > RW)
57.                 printf("h轻了/n");
58.             else printf("h重了/n");
59.         }
60.         else if(LW > RW)
61.         {
62.             printf("g轻了/n");
63.         }
64.         else printf("g重了/n");
65.     }
66.     else if(LW > RW)
67.     {
68.         LW = weight[a] + weight[g] + weight[h];
69.         RW = weight[d] + weight[b] + weight[c];
70.         if(LW > RW)
71.         {
72.             LW = weight[a];
73.             RW = weight[b];
74.             if(LW == RW)
75.                 printf("d轻了/n");
76.             else if(LW > RW)
77.                 printf("a重了/n");
78.         }
79.         else if(LW == RW)
80.         {
81.             LW = weight[e];
82.             RW = weight[a];
83.             if(LW == RW)
84.                 printf("f轻了/n");
85.             else if(LW < RW)
86.                 printf("e轻了/n");
87.         }
88.         else//b,c重了
89.         {
90.             LW = weight[b];
91.             RW = weight[a];
92.             if(LW == RW)
93.                 printf("c重了/n");
94.             else if(LW > RW)
95.                 printf("b重了/n");
96.         }
97.     }
98.     else if(LW < RW)
99.     {
100.         LW = weight[a] + weight[g] + weight[h];
101.         RW = weight[d] + weight[b] + weight[c];
102.         if(LW > RW)//b,c轻了
103.         {
104.             LW = weight[a];
105.             RW = weight[b];
106.             if(LW == RW)
107.                 printf("c轻了/n");
108.             else if(LW > RW)
109.                 printf("b轻了/n");
110.         }
111.         else if(LW == RW)//e,f重了
112.         {
113.             LW = weight[e];
114.             RW = weight[a];
115.             if(LW == RW)
116.                 printf("f重了/n");
117.             else if(LW > RW)
118.                 printf("e重了/n");
119.         }
120.         else//a轻了,d重了
121.         {
122.             LW = weight[b];
123.             RW = weight[a];
124.             if(LW == RW)
125.                 printf("d重了/n");
126.             else if(LW > RW)
127.                 printf("a轻了/n");
128.         }
129.     }
130. }