MLK  Milk Trading
Hareedi and Hanadt live in a village with N houses built next to each other along one
straight roadway with equal distances between adjacent houses. Some people own cows
and sell the milk their cows produce, while others do not own cows and may need to buy
milk.
Every morning, Hareedi and Hanadi transport milk around the village such that everyone
buys or sells the exact number of bottles they want. Transporting one bottle of milk from
one house to an adjacent house results in one unit of work. Fortunately, the number of
milk bottles needed by people is always equal to the number of milk bottles sold by
cow owners.
Task
write a program that is given the number of milk bottles that people at each house needs
to buy or sell, represented as an integer, finds the minimum work necessary to transport
the bottles from sellers to buyers.
Constraints
2 ≤ N ≤ 1,000,000 The number of houses.
1000 ≤ B_{i} ≤ 1000 Integer representing the number of bottles to be bought from or
sold to people at the house at position i.
Input
 Line 1 contains the integer N, the number of houses.
 Each of the next N lines contains an integer B_{i}. If B_{i} > 0 then people in house i are cow
owners and want to sell B_{i} bottles of milk, If B_{i} ≤ 0 then people at house i are not cow owners
and want to buy B_{i} bottles of milk.
Output
 A single line containing a single integer, the minimum work units necessary to
transport the bottle of milk.
Example
Input: 5
5
4
1
3
1
Output: 9
There are 5 houses as shown in the table.
Position
1
2
3
4
5
Bottles
5
4
1
3
1
4 bottles are transported from house 1 to house 2, 1 bottle from house 1 to
house 4, 1 bottle from house 3 to house 4, 1 bottle from house 5 to house 4.

Number of testcases is 28.
hide comments
:D:
20110403 12:46:45
Although time limit seems very thight for that kind of data size, I managed to get AC with scanf. Note that it wasn't the 0.29 time from solutions board, but 2.81 :) 

Ravi Kiran:
20101124 17:18:31
The problem is similar to GERGOVIA with raised constraints and a tighter time limit. 
Added by:  Rofael Emil 
Date:  20101019 
Time limit:  0.203s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  Egyptian Olympiad in Informatics ( EOI ) 2009, August 14  21, Cairo 