hdu Building Shops DP 递推

Building Shops

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 1863    Accepted Submission(s): 665

Problem Description

HDU’s  n classrooms are on a line ,which can be considered as a number line. Each classroom has a coordinate. Now Little Q wants to build several candy shops in these  n classrooms.

The total cost consists of two parts. Building a candy shop at classroom  i would have some cost  ci. For every classroom  P without any candy shop, then the distance between  P and the rightmost classroom with a candy shop on  P's left side would be included in the cost too. Obviously, if there is a classroom without any candy shop, there must be a candy shop on its left side.

Now Little Q wants to know how to build the candy shops with the minimal cost. Please write a program to help him.

 

Input

The input contains several test cases, no more than 10 test cases.
In each test case, the first line contains an integer  n(1≤n≤3000), denoting the number of the classrooms.
In the following  n lines, each line contains two integers  xi,ci(−109≤xi,ci≤109), denoting the coordinate of the  i-th classroom and the cost of building a candy shop in it.
There are no two classrooms having same coordinate.

 

Output

For each test case, print a single line containing an integer, denoting the minimal cost.

 

Sample Input

3 1 2 2 3 3 4 4 1 7 3 1 5 10 6 1

 

Sample Output

5 11

 

Source

2017中国大学生程序设计竞赛 - 女生专场

 

思路：

和背包有点类似，当前点建造或者不建造的两种情况。

只不过用了一点小技巧来处理。