洛谷 P1443 马的遍历

洛谷 P1443 马的遍历

题目

题目

题解

代码（Pascal）

const flag:array[1..8,0..1]of longint=((2,1),(1,2),(-1,2),(2,-1),(-2,-1),(-1,-2),(-2,1),(1,-2));
var n,m,head,tail:longint;
q:array[0..160005]of record
x,y:longint;
end;
map:array[0..405,0..405]of longint;
vis:array[0..405,0..405]of boolean;
procedure init;
begin
readln(n,m,q[1].x,q[1].y);
end;
function check(x,y:longint):boolean;
begin
if (x<1)or(y<1)or(x>n)or(y>m) then exit(false);
if vis[x,y]=true then exit(false);
exit(true);
end;
procedure find(x,y:longint);
begin
inc(tail);vis[x,y]:=true;
q[tail].x:=x;q[tail].y:=y;
map[x,y]:=map[q[head].x,q[head].y]+1;
end;
procedure print(x:longint);
var i,t,y:longint;
begin
t:=0;y:=x;
if x<0 then begin
x:=abs(x);
inc(t);
end;
if (x<=9) then inc(t) else
if (x<=99) then t:=t+2 else
if (x<=999) then t:=t+3 else
if (x<=9999) then t:=t+4;
write(y);
for i:=1 to 5-t do
write(' ');
end;
procedure main;
var i,j,x,y:longint;
begin
fillchar(vis,sizeof(vis),0);
head:=0;tail:=1;
for i:=1 to n do
for j:=1 to m do
map[i,j]:=-1;
map[q[1].x,q[1].y]:=0;
vis[q[1].x,q[1].y]:=true;
while head<tail do
begin
inc(head);
x:=q[head].x;y:=q[head].y;
for i:=1 to 8 do
if check(x+flag[i,0],y+flag[i,1]) then find(x+flag[i,0],y+flag[i,1]);
end;
for i:=1 to n do
begin
for j:=1 to m do print(map[i,j]);
writeln;
end;
end;
begin
init;
main;
end.