CodeForces 289B Polo the Penguin and Matrix

Polo企鹅与矩阵问题

最新推荐文章于 2019-09-29 16:16:59 发布

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最新推荐文章于 2019-09-29 16:16:59 发布 · 743 阅读

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企鹅Polo面临一个n×m矩阵的挑战，需要通过增加或减少某个数d来使得所有矩阵元素相等。文章详细介绍了输入输出格式，并给出样例。解题思路涉及对矩阵元素进行排序，寻找中位数，计算每个元素变为中位数所需d的次数，若存在不能整除的情况则输出-1，否则输出最小操作次数。

Polo the Penguin and Matrix

Description

Little penguin Polo has an n × m matrix, consisting of integers. Let’s index the matrix rows from 1 to n from top to bottom and let’s index the columns from 1 to m from left to right. Let’s represent the matrix element on the intersection of row i and column j as aij.

In one move the penguin can add or subtract number d from some matrix element. Find the minimum number of moves needed to make all matrix elements equal. If the described plan is impossible to carry out, say so.

Input

The first line contains three integers n, m and d(1 ≤ n, m ≤ 100, 1 ≤ d ≤ 104) — the matrix sizes and the d parameter. Next n lines contain the matrix: the j-th integer in the i-th row is the matrix element aij(1 ≤ aij ≤ 104).