标签:alt swap 三个点 接下来 wap max cal 题解 end
题目大意:
题解:很明显建图之后Floyd一下即可。
首先根据勾股定理,可以求出两点之间的距离为√(x1-x2)2(y1-y2)2,然后根据长方形内的三个点求出第四个点,也是根据勾股定理,先求出三个点之中每两个点之间的距离,即b1=√(x1-x2)2(y1-y2)2,b2=√(x1-x3)2(y1-y3)2,b3=√(x2-x3)2(y2-y3)2,如果最长边为b1,则第四个点的坐标为(x1+x2-x3,y1+y2-y3);如果最长边为b2,则第四个点的坐标为(x1-x2+x3,y1-y2+y3);如果最长边为b3,则第四个点的坐标为(-x1+x2+x3,-y1+y2+y3)。
把第四给点搞定之后,再在城市中四个点每两个点之间建一条边,权值为走公路所用花费。接下来在全部城市读入完毕之后,枚举每两个城市之间的每两个点,建一条边,权值为航班花费。
这样就建图完成了,接下来就进行Floyd。
最后枚举起点与终点的每两个点,求出最小花费即为答案。
var n,s,t,a,b,i,j,k,i1,j1,x4,y4,he,l:longint; var ans:double; var d:array[0..500,0..500] of double; var x,y:array[0..100,1..4] of longint; var b1:array[1..100] of longint; function min(a,b:double):double; begin if a<b then exit(a);exit(b); end; procedure swap(var a,b:longint); var t:longint; begin t:=a;a:=b;b:=t; end; procedure max(var a,b,c:longint); var t:longint; begin if a<c then swap(a,c); if a<b then swap(a,b); if b<c then swap(b,c); end; function hh(x,y,x1,y1:longint):double; begin exit(sqrt(sqr(x-x1)+sqr(y-y1))*he); end; procedure xy(x1,y1,x2,y2,x3,y3:longint); var b1,b2,b3:double; begin he:=1; b1:=hh(x1,y1,x2,y2);b2:=hh(x1,y1,x3,y3);b3:=hh(x2,y2,x3,y3); if (b1>=b2) and (b1>=b3) then begin x[j,4]:=abs(x1+x2-x3);y[j,4]:=abs(y1+y2-y3);end else if (b2>=b1) and (b2>=b3) then begin x[j,4]:=abs(x1+x3-x2);y[j,4]:=abs(y1+y3-y2);end else begin x[j,4]:=abs(x2+x3-x1);y[j,4]:=abs(y2+y3-y1);end; end; begin read(n); for i1:=1 to n do begin for j:=1 to 500 do for k:=1 to 500 do d[j,k]:=0; fillchar(b1,sizeof(b1),0); fillchar(x,sizeof(x),0);fillchar(y,sizeof(y),0); read(s,t,a,b);ans:=maxlongint; for j:=1 to s do begin for k:=1 to 3 do read(x[j,k],y[j,k]);read(b1[j]); xy(x[j,1],y[j,1],x[j,2],y[j,2],x[j,3],y[j,3]); he:=b1[j]; for k:=3 downto 1 do for j1:=k-1 downto 0 do begin d[4*j-k,4*j-j1]:=hh(x[j,4-k],y[j,4-k],x[j,4-j1],y[j,4-j1]); d[4*j-j1,4*j-k]:=d[4*j-k,4*j-j1]; end; end; he:=t; for j:=1 to s do for k:=j+1 to s do for l:=3 downto 0 do for j1:=3 downto 0 do begin d[4*j-l,4*k-j1]:=hh(x[j,4-l],y[j,4-l],x[k,4-j1],y[k,4-j1]); d[4*k-j1,4*j-l]:=d[4*j-l,4*k-j1]; end; for k:=1 to 4*s do for i:=1 to 4*s do for j:=1 to 4*s do if d[i,k]+d[k,j]<d[i,j] then d[i,j]:=d[i,k]+d[k,j]; for i:=3 downto 0 do for j:=3 downto 0 do begin ans:=min(d[a*4-i,b*4-j],ans); end; writeln(ans:0:1); end; end.
感谢阅读!
标签:alt swap 三个点 接下来 wap max cal 题解 end
原文地址:http://www.cnblogs.com/ligen1353055672/p/6517379.html