add: 头歌上的隐藏测试集 (#82)

Reviewed-on: PostGuard/Canon#82

open_set/93_dct.pas

@@ -0,0 +1,127 @@
+program main;
+const
+PI = 3.14159265359;
+TWO_PI = 6.28318530718;
+EPSILON = 0.000001;
+var
+test_block, test_dct, test_idct: array [0..7, 0..7] of real;
+dim_x, dim_y, i, j: integer;
+
+function my_fabs(x: real): real;
+begin
+  if x > 0.0 then
+    my_fabs := x
+  else
+    my_fabs := -x;
+end;
+
+function p(x: real):  real;
+begin
+  p := 3 * x - 4 * x * x * x;
+end;
+
+function my_sin_impl(x: real): real;
+begin
+  if my_fabs(x) <= EPSILON then
+    my_sin_impl := x
+  else
+    my_sin_impl := p(my_sin_impl(x / 3.0));
+end;
+
+function my_sin(x: real): real;
+var xx: integer;
+begin
+  if (x > TWO_PI) or (x < -TWO_PI) then
+  begin
+    xx := 1;
+    x := x - 1.0;
+  end;
+  if x > PI then
+    x := x - TWO_PI;
+  if x < -PI then
+    x := x + TWO_PI;
+  my_sin := my_sin_impl(x);
+end;
+
+function my_cos(x: real): real;
+begin
+  my_cos := my_sin(x * PI / 2);
+end;
+
+procedure write_mat(n, m: integer);
+var i,j: integer;
+begin
+  for i := 0 to n - 1 do
+  begin
+    write(test_dct[i, 0]);
+    for j := 1 to m - 1 do
+      write(test_dct[i, j]);
+  end;
+end;
+
+procedure write_mat2(n, m: integer);
+var i,j: integer;
+begin
+  for i := 0 to n - 1 do
+  begin
+    write(test_idct[i, 0]);
+    for j := 1 to m - 1 do
+      write(test_idct[i, j]);
+  end;
+end;
+
+procedure dct(n, m: integer);
+var u, v, i, j: integer;
+begin
+  for u := 0 to n - 1 do
+  begin
+    for v := 0 to m - 1 do
+    begin
+      test_dct[u, v] := 0;
+      for i := 0 to n - 1 do
+      begin
+        for j := 0 to m - 1 do
+        begin
+          test_dct[u, v] := test_dct[u, v] + test_block[i, j] * my_cos(PI / n * (i + 1.0 / 2.0) * u) * my_cos(PI / m * (i + 1.0 / 2.0) * v);
+        end;
+      end;
+    end;
+  end;
+end;
+
+procedure idct(n, m: integer);
+var u, v, i, j: integer;
+begin
+  for u := 0 to n - 1 do
+  begin
+    for v := 0 to m - 1 do
+    begin
+      test_idct[u, v] := 1 / 4.0 * test_dct[0, 0];
+      for i := 1 to n - 1 do
+        test_idct[u, v] := test_idct[u, v] + 1 / 2.0 * test_dct[i, 0];
+      for j := 1 to m - 1 do
+        test_idct[u, v] := test_idct[u, v] + 1 / 2.0 * test_dct[0, j];
+      for i := 1 to n - 1 do
+        for j := 1 to m - 1 do
+          test_idct[u, v] := test_idct[u, v] + test_dct[i, j] * my_cos(PI / n * (u + 1.0 / 2.0) * i) * my_cos(PI / m * (v + 1.0 / 2.0) * j);
+      test_idct[u, v] := test_idct[u, v] * 2.0 / n * 2.0 / m;
+    end;
+  end;
+end;
+
+begin
+  dim_x := 0;
+  dim_y := 0;
+  read(dim_x);
+  read(dim_y);
+
+  for i := 0 to dim_x - 1 do
+    for j := 0 to dim_y - 1 do
+      read(test_block[i, j]);
+  
+  dct(dim_x, dim_y);
+  write_mat(dim_x, dim_y);
+
+  idct(dim_x, dim_y);
+  write_mat2(dim_x, dim_y);
+end.