poj1857 To Europe! To Europe!

思路：

一维dp。

实现：

 #include <cstdio>
 #include <iostream>
 using namespace std;
 const int INF = 0x3f3f3f3f;
 int w[], v[], sum[];
 double dp[];
 int main()
 {
     int b, l, n;
     while (cin >> b >> l >> n, b || l || n)
     {
         for (int i = ; i <= n; i++) dp[i] = INF;
         for (int i = ; i <= n; i++)
         {
             cin >> w[i] >> v[i];
             sum[i] = sum[i - ] + w[i];
         }
         dp[] = (double)l / v[];
         for (int i = ; i <= n; i++)
         {
             int minn = v[i];
             for (int j = i; j >= ; j--)
             {
                 if (sum[i] - sum[j - ] > b) continue;
                 minn = min(minn, v[j]);
                 dp[i] = min(dp[i], dp[j - ] + (double)l / minn);
             }
         }
         printf("%.1f\n", dp[n] * );
     }
     return ;
 }