UVa 140 (枚举排列) Bandwidth

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 const int maxn = 10;
 5 
 6 int id[256], letter[maxn];
 7 char in[1000];
 8 
 9 int main()
10 {
11     freopen("in.txt", "r", stdin);
12 
13     while(scanf("%s", in) == 1 && in[0] != ‘#‘)
14     {
15         int n = 0;
16         for(char ch = ‘A‘; ch <= ‘Z‘; ++ch)
17             if(strchr(in, ch) != NULL)
18             {
19                 //id[ch] = n;
20                 //letter[n++] = ch;
21                 id[ch] = n++;
22                 letter[id[ch]] = ch;
23             }
24 
25         int l = strlen(in), p = 0, q = 0;
26         vector<int> u, v;
27         for(;;)
28         {
29             while(p < l && in[p] != ‘:‘) p++;
30             if(p == l) break;
31             while(q < l && in[q] != ‘;‘) q++;
32             for(int i = p+1; i < q; ++i)
33             {
34                 u.push_back(id[in[p-1]]);
35                 v.push_back(id[in[i]]);
36             }
37             p++; q++;
38         }
39 
40         int P[maxn], bestP[maxn], pos[maxn], ans = n;
41         for(int i = 0; i < n; ++i) P[i] = i;
42         do
43         {
44             for(int i = 0; i < n; ++i) pos[P[i]] = i;
45             int bandwidth = 0;
46             for(int i = 0; i < u.size(); ++i) bandwidth = max(bandwidth, abs(pos[u[i]] - pos[v[i]]));
47             if(bandwidth < ans)
48             {
49                 ans = bandwidth;
50                 memcpy(bestP, P, sizeof(P));
51             }
52         }while(next_permutation(P, P+n));
53 
54         for(int i = 0; i < n; ++i) printf("%c ", letter[bestP[i]]);
55         printf("-> %d\n", ans);
56     }
57 
58     return 0;
59 }