[Luo gu 1387] the largest square

Title Description

In a n*m-only matrix containing 0 and 1, find a maximum square that does not contain 0, and the output edge length.

Input/output format

Input format:

The first behavior of the input file is two integers n,m (1<=n,m<=100), followed by n lines, with m numbers per line, separated by spaces, 0 or 1.

Output format:

An integer, the edge length of the largest square

Input/Output sample

Input Sample # #:

4 40 1 1 11 1 1 00 1 1 01 1 0 1

Sample # # of output:

2

Ideas

DP,F[I,J] Indicates the square size with i,j as the rightmost bottom point.

F[i,j]:=min (min (f[i-1,j],f[i,j-1]), f[i-1,j-1]) +1

varA,f:Array[0.. +,0.. +] ofLongint;    N,m,i,j,ans:longint; functionMax (x,y:longint): Longint; begin      ifX>y ThenExit (x)Elseexit (y); End; functionmin (x,y:longint): Longint; begin      ifX>y ThenExit (Y)Elseexit (x); End; beginFillchar (A,sizeof (a),0); Fillchar (F,sizeof (f),0);      READLN (N,M);  fori:=1  toN Do           forj:=1  toM Doread (a[i,j]);  fori:=1  toN Do           forj:=1  toM Do              ifa[i,j]=1  ThenF[i,j]:=min (min (f[i-1, j],f[i,j-1]), f[i-1, J-1])+1;  fori:=1  toN Do           forj:=1  toM Doans:=Max (ans,f[i,j]);  Writeln (ANS); End.

View Code

[Luo gu 1387] the largest square