双关键字快速排序
快排双关键字
1 var
2 i,j,l,m,n:longint;
3 a,b:array[0..10000]of longint;
4 procedure px(l,r:longint);
5 var
6 i,j,k,m,x,y:longint;
7 begin
8 i:=l;
9 j:=r;
10 x:=a[(i+j) div 2];
11 y:=b[(i+j) div 2];
12 repeat
13 while (a[i]<x)or((a[i]=x)and(b[i]<y)) do inc(i);
14 while (a[j]>x)or((a[j]=x)and(b[j]>y)) do dec(j);
15 if i<=j then
16 begin
17 k:=a[i];a[i]:=a[j];a[j]:=k;
18 k:=b[i];b[i]:=b[j];b[j]:=k;
19 inc(i);
20 dec(j);
21 end;
22 until i>j;
23 if i<r then px(i,r);
24 if j>l then px(l,j);
25 end;
26 begin
27 readln(n);
28 for i:=1 to n do
29 begin
30 read(a[i]);
31 read(b[i]);
32 end;
33 px(1,n);
34 for i:=1 to n do
35 writeln(a[i],' ',b[i]);
36 end.
