1数据结构概述及线性表

 1 type
 2   node=record
 3         x,y:longint;         //integer足矣
 4         d:double;            //real足矣
 5       end;
 6 var
 7   n,i,j,len:longint;
 8   sn:array[1..8000] of node; //如果不想用记录类型，可以用一个二维数组 + 一个一位数组代替
 9 function gcd(x,y:longint):longint;      // function gcd(x,y:longint):longint;
10 begin                                   // begin  
11   if x=0 then gcd:=y                    //   if y=0 then exit(x)
12    else gcd:=gcd(y mod x,x);            //    else exit(gcd(y,x mod y));
13 end;                                    // end
14 
15 {function gcd(x,y:longint):longint;
16 var t:longint;
17 begin
18   while y<>0 do begin
19                   t:=x; x:=y; y:=t mod y;
20                 end;  
21 end;}
22 
23 procedure qsort(l,r:longint);
24 var i,j:longint;
25     mid:double;
26     temp:node;
27 begin
28   i:=l; j:=r;
29   mid:=sn[(l+r) div 2].d;
30    while i<=j do
31     begin
32      while sn[i].d<mid do inc(i);
33      while sn[j].d>mid do dec(j);
34      if i<=j then
35       begin
36         temp:=sn[i]; sn[i]:=sn[j]; sn[j]:=temp;  //若用上述数组则需要写三行交换语句，记录类型直接交换
37         inc(i); dec(j);
38       end;
39     end;
40    if i<r then qsort(i,r);
41    if l<j then qsort(l,j);
42 end;
43 begin
44 assign(input,‘frac1.in‘);
45 assign(output,‘frac1.out‘);
46 reset(input);
47 rewrite(output);
48   readln(n);
49   sn[1].x:=0; sn[1].y:=1; sn[1].d:=0.0;
50   sn[2].x:=1; sn[2].y:=1; sn[2].d:=1.0;
51   len:=2;                               //也可以写成下面这样，省去初始化,直接输出首项和末项
52    for i:=2 to n do                      //for i:=1 to n-1 do
53     for j:=1 to i-1 do                    //for j:=i+1 to n do
54      if gcd(i,j)=1 then
55       begin
56         inc(len);
57         sn[len].x:=j; sn[len].y:=i; sn[len].d:=j/i;
58       end;
59      qsort(1,len);
60     for i:=1 to len do
61      writeln(sn[i].x,‘/‘,sn[i].y);
62 close(input);
63 close(output);
64 end.

 1 { 
 2 ID: qilinar3 
 3 PROG: frac1 
 4 LANG: PASCAL 
 5 }
 6 var
 7     hash:array[0..160*159,1..2] of integer; 
 8     i,j,n:integer; 
 9     t:longint; 
10 begin
11     assign(input,‘frac1.in‘);reset(input); 
12     assign(output,‘frac1.out‘);rewrite(output); 
13     readln(n); 
14     for i:=0 to n do
15         for j:=1 to n do
16             if j>=i then
17             begin
18                 t:=round(i/j*160*159); 
19                 if hash[t][2]=0 then
20                 begin     hash[t][1]:=i;     hash[t][2]:=j;     end; 
21             end; 
22     for i:=0 to 160*159 do if hash[i][2]<>0 then writeln(hash[i][1],‘/‘,hash[i][2]); 
23     close(input);close(output); 
24 end.