usaco3.1.1 agrinet
http://hi.baidu.com/raulliubo/blog/item/b91fec249f207e378744f9a6.html
!!神奇了。。刚才又交了一遍kruskal的程序,竟然tmd AC了。。难道这就是传说中的RPWT。。我的RP低到极点了。
USER: BO LIU [raulliu2]
TASK: agrinet
LANG: PASCAL
Compiling...
Compile: OK
Executing...
Test 1: TEST OK [0 secs]
Test 2: TEST OK [0 secs]
Test 3: TEST OK [0 secs]
Test 4: TEST OK [0.004 secs]
Test 5: TEST OK [0.004 secs]
Test 6: TEST OK [0 secs]
Test 7: TEST OK [0.004 secs]
Test 8: TEST OK [0.004 secs]
Test 9: TEST OK [0.004 secs]
Test 10: TEST OK [0.012 secs]
All tests OK.
Your program ('agrinet') produced all correct answers! This is your
submission #4 for this problem. Congratulations!
标准MST,啥优化都不要。。刚开始用kruskal做的。。不知道怎么回事老是WA on test5....很郁闷的说。只得改用prim。。。我可不喜欢prim啊。。。。
my ugly code :
PRIM:
{
PROG:agrinet
ID:parachutes
LANG:PASCAL
}
var
map : array[1 .. 100, 1 .. 100] of longint;
d : array[1 .. 100] of longint;
mark : array[1 .. 100] of boolean;
n, i, ans, j : longint;
procedure prim;
var
i, j, min, minj : longint;
begin
fillchar(mark, sizeof(mark), 0);
mark[1] := true;
for i := 1 to n do begin
if map[1, i] <> 0 then d[i] := map[1, i]
else d[i] := maxlongint;
end;
ans := 0;
for i := 2 to n do begin
min := maxlongint;
for j := 1 to n do begin
if (not mark[j]) and (d[j] < min) then begin
min := d[j];
minj := j;
end;
end;
mark[minj] := true;
inc(ans, d[minj]);
for j := 1 to n do
if (d[j] > map[minj, j]) and (map[minj, j] <> 0) then
d[j] := map[minj, j];
end;
end;
begin
assign(input,'agrinet.in'); reset(input);
assign(output,'agrinet.out'); rewrite(output);
readln(n);
for i := 1 to n do begin
for j := 1 to n do
read(map[i, j]);
readln;
end;
prim;
writeln(ans);
close(input); close(output);
end.
===================================强大的分割线====================================
{
PROG:agrinet
ID:parachutes
LANG:PASCAL
}
var
x, j, tot, i, n : longint;
l, a, b : array[1 .. 10000] of longint;
f : array[1 .. 100] of longint;
v : array[1 .. 100, 1 .. 100] of boolean;
procedure qsort(ll, rr : longint);
var
i, j, mid, temp : longint;
begin
i := ll; j := rr; mid := l[(i + j) shr 1];
repeat
while l[i] < mid do inc(i);
while l[j] > mid do dec(j);
if i <= j then begin
temp := l[i]; l[i] := l[j]; l[j] := temp;
temp := a[i]; a[i] := a[j]; a[j] := temp;
temp := b[i]; b[i] := b[j]; b[j] := temp;
inc(i); dec(j);
end;
until i > j;
if i < rr then qsort(i, rr);
if ll < j then qsort(ll, j);
end;
function find(x : longint) : longint;
var
tmp : longint;
begin
if f[x] = x then exit(x)
else exit(find(f[x]));
end;
procedure union(u, v : longint);
var
fu, fv : longint;
begin
fu := find(u);
fv := find(v);
f[fv] := fu;
end;
procedure kruskal;
var
cnt, i, ans : longint;
begin
for i := 1 to n do f[i] := i;
cnt := 0;
ans := 0;
for i := 1 to tot do
if (find(a[i]) <> find(b[i])) then begin
union(a[i], b[i]);
ans := ans + l[i];
inc(cnt);
if cnt = n - 1 then break;
end;
writeln(ans);
end;
begin
assign(input,'agrinet.in'); reset(input);
assign(output,'agrinet.out'); rewrite(output);
fillchar(v, sizeof(v), 0);
tot := 0;
readln(n);
for i := 1 to n do begin
for j := 1 to n do begin
read(x);
if (not v[i, j]) and (i <> j) then begin
inc(tot);
a[tot] := i;
b[tot] := j;
v[i, j] := true;
v[j, i] := true;
l[tot] := x;
end;
end;
readln;
end;
qsort(1, tot);
kruskal;
close(input); close(output);
end.
我的确很闲。。闲的没事非要写kruskal。。谁让我喜欢呢。。