[Vijos 拼图]

[题目来源]：vijos@潘帕斯雄鹰生日模拟赛T2

[关键字]：搜索

[题目大意]：给出n个不规则图形，要求用所有的图形拼成一个正方形是否可行，可行则输出方案。

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[分析]：虽然一眼就能看出搜索但是要想实现却并不是太简单。就是枚举每一个图形可以放在哪，然后放置在搜索下一个。判断时要利用给出的矩形判断。

[代码]：

View Code

  1 type
  2   rec = record
  3     x, y: longint;
  4     map: array[0..200,0..200] of longint;
  5   end;
  6 var
  7   n, s, bc: longint;
  8   c: array[0..20,0..20] of word;
  9   a: array[0..200] of rec;
 10 
 11 procedure print(x: longint);
 12 var
 13   i, j: longint;
 14 begin
 15   if x = -1 then
 16     begin
 17       writeln('N');
 18       close(input);
 19       close(output);
 20       halt;
 21     end;
 22   if x = -2 then
 23     begin
 24       writeln(1);
 25       close(input);
 26       close(output);
 27       halt;
 28     end;
 29   for i := 1 to bc do
 30     begin
 31       for j := 1 to bc do write(c[i,j]);
 32       writeln;
 33     end;
 34   close(input);
 35   close(output);
 36   halt;
 37 end;
 38 
 39 procedure init;
 40 var
 41   i, j, k: longint;
 42   ch: char;
 43 begin
 44   readln(n);
 45   for k := 1 to n do
 46     begin
 47       readln(a[k].x,a[k].y);
 48       for i := 1 to a[k].x do
 49         begin
 50       for j := 1 to a[k].y do
 51         begin
 52           read(ch);
 53           a[k].map[i,j] := ord(ch)-48;
 54           inc(s,ord(ch)-48);
 55         end;
 56       readln;
 57     end;
 58     end;
 59   bc := trunc(sqrt(s));
 60   if bc <> sqrt((s)) then print(-1);
 61   if s = 1 then print(-2);
 62 end;
 63 
 64 function cleck(x1, y1, w: longint):boolean;
 65 var
 66   i, j, x, y: longint;
 67 begin
 68   if a[w].x+x1-1 > bc then exit(false);
 69   if a[w].y+y1-1 > bc then exit(false);
 70   for i := x1 to a[w].x+x1-1 do
 71     for j := y1 to a[w].y+y1-1 do
 72       if (a[w].map[i-x1+1,j-y1+1] = 1) then
 73         if c[i,j] <> 0 then exit(false);
 74   exit(true);
 75 end;
 76 
 77 procedure put(x1 ,y1, w: longint);
 78 var
 79   i, j: longint;
 80 begin
 81   for i := x1 to x1+a[w].x-1 do
 82     for j := y1 to y1+a[w].y-1 do
 83       if a[w].map[i-x1+1,j-y1+1] = 1 then c[i,j] := w;
 84 end;
 85 
 86 procedure dfs(k: longint);
 87 var
 88   i, j: longint;
 89   t: array[0..20,0..20] of word;
 90 begin
 91   if k > n then print(1);
 92 //  writeln(k);
 93   for i := 1 to bc do
 94     for j := 1 to bc do
 95       if cleck(i,j,k) then
 96     begin
 97       t := c;
 98       put(i,j,k);
 99       dfs(k+1);
100       c := t;
101     end;
102 end;
103 
104 begin
105   assign(input,'c:\1.in');reset(input);
106   assign(output,'c:\1.out');rewrite(output);
107   init;
108   dfs(1);
109 //  writeln('asdf');
110   print(-1);
111   readln(n);
112 end.