poj-2393-Yogurt factory

Love The Way You Lie 2022-05-20 05:25 102阅读 0赞

Yogurt factory

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 <tbody> 
  <tr> 
   <td><strong>Time Limit:</strong>&nbsp;1000MS</td> 
   <td>&nbsp;</td> 
   <td><strong>Memory Limit:</strong>&nbsp;65536K</td> 
  </tr> 
  <tr> 
   <td><strong>Total Submissions:</strong>&nbsp;13761</td> 
   <td>&nbsp;</td> 
   <td><strong>Accepted:</strong>&nbsp;6904</td> 
  </tr> 
 </tbody> 
</table>

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.

题目大意：一个工厂生产酸奶，酸奶可以放在仓库里不会过期，然后告诉你接下来N周的酸奶生产价格，以及放在仓库里的租金，下面是N周的酸奶生产价格以及用户需求量，求如何生产才能使付出最少

思路：贪心，将本周的生产价格和下周的生产价格和租金加起来相比，取最小，然后乘上单位量就是最小租金

代码：

#include<map>
    #include<stack>
    #include<cmath>
    #include<string>
    #include<cstdio>
    #include<cstring>
    #include<cstdlib>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    #define maxn 11000
    #define ll long long
    int c[maxn],y[maxn];
    int main()
    {
       int n,s;
       while(scanf("%d%d",&n,&s)!=EOF)
       {
           int i,j,k;
           ll ans=0;
           for(i=0;i<n;i++)
           {
               scanf("%d%d",&c[i],&y[i]);
               if(i>=1)
               {
                   c[i]=min(c[i],c[i-1]+s);
               }
           }
           for(i=0;i<n;i++)
           {
               ans+=c[i]*y[i];
           }
           printf("%lld\n",ans);
       }
        return 0;
    }