Graph And Its Complement

题意翻译

一张无向图一共有n个点,a个联通块,它的补图一共有b个联通块,如果能构造出这张图输出'YES'并输出它的邻接矩阵，否则输出'NO' 输入: 三个整数n,a,b 输出： 如果有解输出'YES'和邻接矩阵，否则输出'NO' 感谢@zhaotiensn 提供翻译

题目描述

Given three numbers $ n, a, b $ . You need to find an adjacency matrix of such an undirected graph that the number of components in it is equal to $ a $ , and the number of components in its complement is $ b $ . The matrix must be symmetric, and all digits on the main diagonal must be zeroes. In an undirected graph loops (edges from a vertex to itself) are not allowed. It can be at most one edge between a pair of vertices. The adjacency matrix of an undirected graph is a square matrix of size $ n $ consisting only of "0" and "1", where $ n $ is the number of vertices of the graph and the $ i $ -th row and the $ i $ -th column correspond to the $ i $ -th vertex of the graph. The cell $ (i,j) $ of the adjacency matrix contains $ 1 $ if and only if the $ i $ -th and $ j $ -th vertices in the graph are connected by an edge. A connected component is a set of vertices $ X $ such that for every two vertices from this set there exists at least one path in the graph connecting this pair of vertices, but adding any other vertex to $ X $ violates this rule. The complement or inverse of a graph $ G $ is a graph $ H $ on the same vertices such that two distinct vertices of $ H $ are adjacent if and only if they are not adjacent in $ G $ .

输入输出格式

输入格式

In a single line, three numbers are given $ n, a, b \,(1 \le n \le 1000, 1 \le a, b \le n) $ : is the number of vertexes of the graph, the required number of connectivity components in it, and the required amount of the connectivity component in it's complement.

输出格式

If there is no graph that satisfies these constraints on a single line, print "NO" (without quotes). Otherwise, on the first line, print "YES"(without quotes). In each of the next $ n $ lines, output $ n $ digits such that $ j $ -th digit of $ i $ -th line must be $ 1 $ if and only if there is an edge between vertices $ i $ and $ j $ in $ G $ (and $ 0 $ otherwise). Note that the matrix must be symmetric, and all digits on the main diagonal must be zeroes. If there are several matrices that satisfy the conditions — output any of them.

输入输出样例

输入样例 #1

3 1 2

输出样例 #1

YES
001
001
110

输入样例 #2

3 3 3

输出样例 #2

NO