bzoj 3035 pascal

这道题也是一个二分图匹配的题，也需要用匈牙利算法，但需要小小的改进

 

中间需要一个二分搜答案的过程，这也是其中的一个小小的变型吧

 

需要注意一下读入，他是有分钟有秒，所以不要被坑哦

 

最后不说废话，直接上代码

 

/**************************************************************

    Problem: 3035

    User: Davidliu

    Language: Pascal

    Result: Accepted

    Time:236 ms

    Memory:4216 kb

****************************************************************/

 

var

 

    n, m, t2, v                     :longint;

 

    t1                              :real;

 

    dis                             :array[0..100,0..100] of real;

 

    ans                             :real;

 

    pre, other, last                :array[0..200100] of longint;

 

    link                            :array[0..100] of longint;

 

    flag                            :array[0..100] of boolean;

 

    x1, x2, y1, y2                  :array[0..100] of longint;

 

    l                               :longint;

 

    len                             :array[0..200100] of real;

 

 

 

procedure init;

 

var

 

    i, j                            :longint;

 

begin

 

    read(n,m,t1,t2,v);

 

    for i:=1 to m do read(x2[i],y2[i]);

 

    for i:=1 to n do read(x1[i],y1[i]);

 

    t1:=t1/60;

 

    for i:=1 to n do

 

        for j:=1 to m do

 

            dis[i,j]:=sqrt((x1[i]-x2[j])*(x1[i]-x2[j])+(y1[i]-y2[j])*(y1[i]-y2[j]));

 

end;

 

 

 

procedure connect(x,y:longint; z:real);

 

begin

 

    inc(l);

 

    pre[l]:=last[x];

 

    last[x]:=l;

 

    other[l]:=y;

 

    len[l]:=z;

 

end;

 

 

 

function find(i:longint):boolean;

 

var

 

    q, p                            :longint;

 

begin

 

    q:=last[i];

 

    while q<>0 do

 

    begin

 

        p:=other[q];

 

        if (not flag[p]) then

 

        begin

 

            flag[p]:=true;

 

            if (link[p]=0) or (find(link[p])) then

 

            begin

 

                link[p]:=i;

 

                exit(true);

 

            end;

 

        end;

 

        q:=pre[q];

 

    end;

 

    exit(false);

 

end;

 

 

 

procedure judge(low,high:real);

 

var

 

    mid                             :real;

 

    tot                             :longint;

 

    i, j, ll                        :longint;

 

    k                               :longint;

 

    count                           :longint;

 

begin

 

    if high<low then exit;

 

    fillchar(last,sizeof(last),0);

 

    fillchar(link,sizeof(link),0);

 

    tot:=0;

 

    l:=1;

 

    mid:=(low+high)/2;

 

    k:=trunc(((mid-t1)/(t1+t2))+1);

 

    for i:=1 to n do

 

        for ll:=1 to k do

 

        begin

 

            inc(tot);

 

            for j:=1 to m do

 

                if (((mid-t1)-(ll-1)*(t1+t2))*v)>=dis[i,j]

 

                    then connect(tot,j,dis[i,j]/v+(ll-1)*(t1+t2)+t1);

 

        end;

 

    count:=0;

 

 

 

    for i:=1 to tot do

 

    begin

 

        fillchar(flag,sizeof(flag),false);

 

        if find(i) then inc(count);

 

    end;

 

 

 

    if (high-low<1e-8) then

 

        if count>=m then

 

        begin

 

            ans:=mid;

 

        end else exit;

 

    if count>=m then

 

    begin

 

        ans:=mid;

 

        judge(low,mid-1e-8);

 

    end else judge(mid+1e-8,high);

 

end;

 

 

 

procedure main;

 

begin

 

    judge(1,30000);

 

    writeln(ans:0:6);

 

end;

 

 

 

begin

 

    init;

 

    main;

 

end.