信息学集训队作业0035-fence

1、题目0035 Fence(篱笆)题目来源：Ural推荐者：金恺英文原文FenceTime Limit: 1 secondMemory Limit: 1000KProblemWorkers are going to enclose a new working region with a fence. For their convenience the enclosed area has to be as large as possible. They have N rectangular blocks to build the fence. The length of the i-th bloc

2、k is Li meters. All blocks have the same height of 1 meter. The workers are not allowed to break blocks into parts. All blocks must be used to build the fence. InputThe first line of the input file contains one integer N (3 = N = 100).The following N lines describe fence blocks. Each block is repres

3、ented by its length in meters (integer number, 1 = Li = 100). OutputWrite to the output file one non-negative number S - maximal possible area of the working region (in square meters). S must be written with two digits after the decimal point. If it is not possible to construct the fence from the sp

4、ecified blocks, write 0.00. Sample OutputSample Output28.00Sample Input410554中文试题篱笆Time Limit: 1 secondMemory Limit: 1000K问题：工人们将要用栅栏围成一个新的工作区域。为了方便生产，围成的区域要尽量大. 他们用N个木料来建造栅栏。第i个木料的长度是Li米。所有的木料有相同的高度1米。工人们不能够切割木料。所有的N个木料必须使用。 输入：第一行包括一个整数N (3 = N = 100).接下来N行描述木料.。每一个木料用他的长度（单位米，1 = Li r0 Fr 2。因为题目只要求精确到小数点后4位，所以二分求解半径即可。圆心在形外。类似于Fr，定义函数，于是满足r 0。同理，二分求解。 算法在思维、空间、时间上均不复杂，可谓优秀。刘汝佳： 我用过二分法以外