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 }