HD2059龟兔赛跑(DP)

题目链接

直接拿来当贪心做了=_=,然后就懵逼了

动态规划,本弱真没想到=_=

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <algorithm>
 5 using namespace std;
 6 const double eps = 0.000001;
 7 const int INF = 0xffffff;
 8 int station[110];
 9 double dp[110];
10 int l, n, c, t, vr, vt1, vt2;
11 double get_time(int s, int tempc)
12 {
13     double gtime = 0;
14     if(s > tempc)
15     {
16         gtime += 1.0 * tempc / vt1;
17         gtime += (s - tempc) * 1.0 / vt2;
18     }
19     else
20     {
21         gtime += s * 1.0 / vt1;
22     }
23     return gtime;
24 }
25 int is_chong(int s, int tempc)
26 {
27     double chong_time = t + get_time(s, c);
28     double not_chong_time = get_time(s, tempc);
29     if(not_chong_time - chong_time > eps)
30         return 1;
31     return 0;
32 }
33 double get_min(double x, double y)
34 {
35     if(x - y > eps)
36         return y;
37     return x;
38 }
39 int main()
40 {
41     while(scanf("%d", &l) != EOF)
42     {
43         scanf("%d%d%d", &n, &c, &t);
44         scanf("%d%d%d", &vr, &vt1, &vt2);
45         for(int i = 1; i <= n; i++)
46             scanf("%d", &station[i]);
47         station[n + 1] = l;
48         double rtime = 1.0 * l / vr;
49         station[0] = 0;
50         dp[0] = 0;
51         for(int i = 1; i <= n + 1; i++)
52         {
53             dp[i] = INF;
54             for(int j = i - 1; j >= 0; j--)
55             {
56                 double tempTime = 0;
57                 int s = station[i] - station[j];
58                 if(s > c)
59                 {
60                     tempTime = 1.0 * c / vt1;
61                     tempTime += (s - c) * 1.0 / vt2;
62                 }
63                 else
64                     tempTime = s * 1.0 / vt1;
65                 if(j)
66                     tempTime += t;
67                 dp[i] = get_min(dp[i], dp[j] + tempTime);
68             }
69             /*
70             int s = station[i] - station[i - 1];
71             if(s > tempc)
72             {
73                 gtime += 1.0 * tempc / vt1;
74                 gtime += (s - tempc) * 1.0 / vt2;
75                 tempc = 0;
76             }
77             else
78             {
79                 gtime += s * 1.0 / vt1;  // 不知道什么时候手贱,这里把s写成了c,浪费了半个小时
80                 tempc = tempc - s;
81             }
82             if(is_chong(station[i + 1] - station[i], tempc))
83             {
84                 gtime += t;
85                 tempc = c;
86             }
87             */
88         }
89         //gtime += get_time(l - station[n], tempc);
90         if(dp[n + 1] - rtime > eps)
91             printf("Good job,rabbit!
");
92         else
93             printf("What a pity rabbit!
");
94     }
95     return 0;
96 }
View Code
原文地址:https://www.cnblogs.com/zhaopAC/p/5313211.html