UVa 116 (多段图的最短路) Unidirectional TSP

 1 #include <cstdio>
 2 #include <algorithm>
 3 
 4 const int maxm = 15;
 5 const int maxn = 100 + 5;
 6 const int INF = 1000000000;
 7 int m, n, d[maxm][maxn], a[maxm][maxn], next[maxm][maxn];
 8 
 9 int main(void)
10 {
11     //freopen("116in.txt", "r", stdin);
12     while(scanf("%d%d", &m, &n) == 2)
13     {
14         int ans = INF, first = 0;
15         for(int i = 0; i < m; ++i)
16             for(int j = 0; j < n; ++j)
17                 scanf("%d", &a[i][j]);
18         for(int j = n-1; j >= 0; --j)
19         {
20             for(int i = 0; i < m; ++i)
21             {
22                 if(j == n-1)    d[i][j] = a[i][j];    //±ß½ç
23                 else
24                 {
25                     int row[3] = {i-1, i, i+1};
26                     if(i == 0)    row[0] = m-1;
27                     if(i == m-1)    row[2] = 0;
28                     std::sort(row, row + 3);        //ÅÅÐòÒÔ±£Ö¤×ÖµäÐò×îС
29                     d[i][j] = INF;
30                     for(int k = 0; k < 3; ++k)
31                     {
32                         int v = d[row[k]][j+1] + a[i][j];
33                         if(v < d[i][j])
34                         {
35                             d[i][j] = v;
36                             next[i][j] = row[k];
37                         }
38                     }
39                 }
40                 if(j == 0 && d[i][j] < ans)
41                 {
42                     ans = d[i][j];
43                     first = i;
44                 }
45             }
46         }
47         printf("%d", first+1);
48         int i = next[first][0];
49         for(int j = 1; j < n; ++j)
50         {
51             printf(" %d", i+1);
52             i = next[i][j];
53         }
54         printf("\n%d\n", ans);
55     }
56 
57     return 0;
58 }