递推DP URAL 1031 Railway Tickets

题目传送门

 1 /*
 2     简单递推DP：读题烦！在区间内的都更新一遍，dp[]初始化INF
 3     注意：s1与s2大小不一定，坑！
 4     详细解释：http://blog.csdn.net/kk303/article/details/6847948
 5 */
 6 #include <cstdio>
 7 #include <iostream>
 8 #include <algorithm>
 9 #include <cstring>
10 #include <string>
11 #include <queue>
12 using namespace std;
13
14 const int MAXN = 1e4 + 10;
15 const int INF = 0x3f3f3f3f;
16 int C[4], L[4];
17 int dp[MAXN], a[MAXN];
18
19 int main(void)        //URAL 1031 Railway Tickets
20 {
21     //freopen ("Y.in", "r", stdin);
22
23     while (scanf ("%d%d%d%d%d%d", &L[1], &L[2], &L[3], &C[1], &C[2], &C[3]) == 6)
24     {
25         int n;    scanf ("%d", &n);
26         int s1, s2;
27         scanf ("%d%d", &s1, &s2);
28         if (s1 > s2)    swap (s1, s2);
29         a[1] = 0;
30         for (int i=2; i<=n; ++i)
31         {
32             scanf ("%d", &a[i]);    dp[i] = INF;
33         }
34
35         dp[s1] = 0;
36         for (int i=s1+1; i<=s2; ++i)
37         {
38             for (int j=1; j<=3; ++j)
39             {
40                 int k = i - 1;
41                 while (k >= s1)
42                 {
43                     if (a[i] - a[k] > L[j])    break;
44                     if (dp[i] > dp[k] + C[j])    dp[i] = dp[k] + C[j];
45                     k--;
46                 }
47             }
48         }
49
50         printf ("%d\n", dp[s2]);
51     }
52
53     return 0;
54 }