UVa 10014 Simple calculations （数学）

UVa 10014 Simple calculations （数学）2014-07-14 csdn博客 synapse710014 - Simple calculations

Time limit: 3.000 seconds

http://uva.onlinejudge.org/index.php？option=com_onlinejudge&Itemid=8&category=99&page=show_problem&problem=955

The Problem

There is a sequence of n+2 elements a₀, a₁,…, a_n+1 （n <= 3000; -1000 <= a_i 1000）. It is known that a_i = （a_i–1 + a_i+1）/2 – c_i for each i=1, 2, ..., n. You are given a₀, a_n+1, c₁, ... , c_n. Write a program which calculates a₁.

The Input

The first line is the number of test cases, followed by a blank line.

For each test case, the first line of an input file contains an integer n. The next two lines consist of numbers a₀ and a_n+1 each having two digits after decimal point, and the next n lines contain numbers c_i （also with two digits after decimal point）, one number per line.

Each test case will be separated by a single line.

The Output

For each test case, the output file should contain a₁ in the same format as a₀ and a_n+1.

Print a blank line between the outputs for two consecutive test cases.

Sample Input

1150.5025.5010.15

Sample Output

27.85

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