Preparando MOJI

Graph And Its Complement

2000ms 262144K

Description:

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 $$$G$$$.

Input:

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.

Output:

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.

Sample Input:

3 1 2

Sample Output:

YES
001
001
110

Sample Input:

3 3 3

Sample Output:

NO

Informação

Codeforces

Provedor Codeforces

Código CF990D

Tags

constructive algorithmsgraphsimplementation

Submetido 0

BOUA! 0

Taxa de BOUA's 0%

Datas 09/05/2023 09:34:59

Relacionados

Nada ainda