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poj 2393 Yogurt factory

时间:2015-05-06 22:49:00      阅读:284      评论:0      收藏:0      [点我收藏+]

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http://poj.org/problem?id=2393

Yogurt factory
Time Limit: 1000MS   Memory Limit: 65536K
Total Submissions: 7341   Accepted: 3757

Description

The cows have purchased a yogurt factory that makes world-famous Yucky Yogurt. Over the next N (1 <= N <= 10,000) weeks, the price of milk and labor will fluctuate weekly such that it will cost the company C_i (1 <= C_i <= 5,000) cents to produce one unit of yogurt in week i. Yucky‘s factory, being well-designed, can produce arbitrarily many units of yogurt each week. 

Yucky Yogurt owns a warehouse that can store unused yogurt at a constant fee of S (1 <= S <= 100) cents per unit of yogurt per week. Fortuitously, yogurt does not spoil. Yucky Yogurt‘s warehouse is enormous, so it can hold arbitrarily many units of yogurt. 

Yucky wants to find a way to make weekly deliveries of Y_i (0 <= Y_i <= 10,000) units of yogurt to its clientele (Y_i is the delivery quantity in week i). Help Yucky minimize its costs over the entire N-week period. Yogurt produced in week i, as well as any yogurt already in storage, can be used to meet Yucky‘s demand for that week.

Input

* Line 1: Two space-separated integers, N and S. 

* Lines 2..N+1: Line i+1 contains two space-separated integers: C_i and Y_i.

Output

* Line 1: Line 1 contains a single integer: the minimum total cost to satisfy the yogurt schedule. Note that the total might be too large for a 32-bit integer.

Sample Input

4 5
88 200
89 400
97 300
91 500

Sample Output

126900

Hint

OUTPUT DETAILS: 
In week 1, produce 200 units of yogurt and deliver all of it. In week 2, produce 700 units: deliver 400 units while storing 300 units. In week 3, deliver the 300 units that were stored. In week 4, produce and deliver 500 units. 

Source

 
 
 
分析:

简单DP~求最少的花费~

题目是说你每周可以生产牛奶,每周生产的价格为Ci,每周需要上交的牛奶量Yi,你可以选择本周生产牛奶,也可选择提前几周生产出存储在仓库中(仓库无限大,而且保质期不考虑),每一周存仓库牛奶需要花费S元,让你求出所有周的需求量上交的最少花费。

将S转换到花费中~

 

 

AC代码:

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 using namespace std;
 5 const int maxn=10011;
 6 int n,s;
 7 int y[maxn],c[maxn];
 8 int main()
 9 {
10     while(scanf("%d%d",&n,&s)!=EOF)
11     {
12     for(int i=0;i<n;i++)
13         scanf("%d%d",&c[i],&y[i]);
14     long long ans=0;
15     for(int i=1;i<n;i++)
16         c[i]=min(c[i-1]+s,c[i]);
17     for(int i=0;i<n;i++)
18         ans+=c[i]*y[i];
19     printf("%lld\n",ans);
20     }
21     return 0;
22 }

 

 

AC代码:

技术分享
 1 #include<cstdio>
 2 
 3 using namespace std;
 4 int a[10005],b[10005];
 5 
 6 int main() {
 7     int n,s;
 8     while(~scanf("%d %d",&n,&s)) {
 9         for(int i = 0;i < n;i++) {
10             scanf("%d %d",&a[i],&b[i]);
11         }
12         
13         __int64 res = a[0] * b[0];
14         for(int i = 1;i < n;i++) {
15             int mi = 10000000,pos = -1;
16             for(int j = 0;j < i;j++) {
17                 if(mi > s * (i - j) && (a[i] - a[j] > s * (i - j)) ) {
18                     mi = s * (i - j);
19                     pos = j;
20                 }
21             }
22             if(pos != -1)
23                 res += a[pos] * b[i] + mi * b[i];
24             else
25                 res += a[i] * b[i];
26         }
27         printf("%I64d\n",res);
28     }
29     return 0;
30 }
View Code

 

poj 2393 Yogurt factory

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原文地址:http://www.cnblogs.com/jeff-wgc/p/4483304.html

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