Use a batch processing program in Windows

In progressAlgorithmWhen it comes to competition-related questions, it is easy to think of a simple algorithm that can ensure that it is completely correct, but it will time out. Efficient algorithms cannot be fully written. At this time, you can write a simple algorithm and generate a data.ProgramVerify the correctness of the efficient algorithm with a file Comparison Program.

In Windows, the FC command provides the file comparison function. Although batch processing is not as powerful as Bash in Linux, it is enough to write an automatic Comparison Program.

The following uses reverse order as an example. The question is similar to poj3067, and the reverse order is obtained after sorting. Data volume n = 300000. It is easy to think of enumeration Reverse Order pairs similar to Bubble sorting and write them first. Name it standard. Pas

 Const 
Maxn = 500000 ;
 Type  
Car = Record X, V: longint End ;

 VaR 
A:Array [ 0 .. Maxn] Of CAR;
N: longint;
I, J: longint;
Sum: longint;

 Procedure Swap ( VaR A, B: Car );
 VaR 
Temp: car;
 Begin 
Temp: =;
A: = B;
B: = temp;
 End ;

 Begin 
Readln (N );
 For I: = 1   To N Do 
Readln (A [I]. X, a [I]. V );
 For I: = 1   To N- 1   Do 
 For J: = I + 1   To N Do 
 If A [I]. x> A [J]. x Then 
Swap (A [I], a [J]);
 For I: = 1   To N- 1   Do 
 For J: = I + 1   To N Do 
 If A [I]. V> A [J]. vThen 
INC (SUM );
Writeln (SUM );
 End .

Only by using advanced algorithms such as Merge Sorting to implement nlogn can this problem be avoided. The name is overtaking. Pas. The program uses the merge sort to sort the order, and then copies the merge sort to change it to the statistical process of reverse order.

 Const 
Maxn = 500000 ;
 Type  
Car = Record X, V: longint End ;

 VaR 
Temp,:Array [ 0 .. Maxn] Of CAR;
N: longint;
I: longint;
Sum: int64;

 Procedure Swap ( VaR A, B: Car );
 VaR 
Temp: car;
 Begin 
Temp: =;
A: = B;
B: = temp;
 End ;

 Procedure Qsort (L, R: longint );
 VaR 
I, j, M: longint;
 Begin 
I: = L; J: = r; M: = A [(L + r) Div   2 ]. X;
 Repeat 
 While (A [I]. x <m) Do INC (I );
 While (A [J]. x> m) Do Dec (j );
If I <= J Then 
 Begin 
Swap (A [I], a [J]);
INC (I );
Dec (j );
 End ;
 Until I> J;
 If L <j Then 
Qsort (L, J );
 If I <r Then 
Qsort (I, R );
End ;

 Procedure Merge (left, mid, right: longint );
 VaR 
I, j, P, K: longint;
 Begin 
K: = left;
I: = left;
J: = Mid + 1 ;
 While (I <= mid) And (J <= right) Do 
 Begin 
If A [I]. x <= A [J]. x Then 
 Begin 
Temp [k]: = A [I];
INC (I );
INC (k );
 End 
 Else   Begin 
Temp [k]: = A [J];
INC (j );
INC (k );
 End ;
 End ;
For P: = I To Mid Do 
 Begin 
Temp [k]: = A [p];
INC (k );
 End ;
 For P: = J To Right Do 
 Begin 
Temp [k]: = A [p];
INC (k );
 End ;
For I: = left To Right Do 
A [I]: = temp [I];
 End ;

 Procedure Merge_sort (left, right: longint );
 VaR 
Mid: longint;
 Begin 
 If Left> = right Then     
Exit;
Mid: = (left + right) SHR1 ;
Merge_sort (left, mid );
Merge_sort (Mid + 1 , Right );
Merge (left, mid, right );
 End ;



 Procedure Merge2 (left, mid, right: longint );
 VaR 
I, j, P, K: longint;
 Begin 
K: = left;
I: = left;
J: = Mid + 1 ;
 While (I <= mid) And (J <= right) Do 
 Begin 
 If A [I]. v <= A [J]. v Then 
 Begin 
Temp [k]: = A [I];
INC (I );
INC (k );
 End 
 Else   Begin 
INC (sum, mid-I + 1 );
Temp [k]: = A [J];
INC (j );
INC (k );
 End ;
 End ;
 For P: = I To Mid Do 
 Begin 
Temp [k]: = A [p];
INC (k );
 End ;
For P: = J To Right Do 
 Begin 
Temp [k]: = A [p];
INC (k );
 End ;
 For I: = left To Right Do 
A [I]: = temp [I];
 End ;

 Procedure Merge_sort2 (left, right: longint );
 VaR 
Mid: longint;
 Begin 
 If Left> = right Then     
Exit;
Mid: = (left + right) SHR 1 ;
Merge_sort2 (left, mid );
Merge_sort2 (Mid + 1 , Right );
Merge2 (left, mid, right );
 End ;


 Procedure Select_sort;
 VaR  
I, J: longint;
 Begin 
 For I: = 1   To N- 1   Do 
 For J: = I + 1   To N Do 
 If A [I]. x> A [J]. x Then 
Swap (A [I], a [J]);
 End ;

 Begin 

Readln (N );
 For I: = 1   To N Do 
 Begin 
Readln (A [I]. X, a [I]. V );
 End ;
Merge_sort ( 1 , N );
Merge_sort2 (1 , N );
Writeln (SUM );


 End .

Then write a data generator. The data created here is simple. Just generate a random number.

 
Const
INF =199303170;
Maxn =3000;

VaR
I, n: longint;
Begin
Randomize;
N: = random (maxn );
Writeln (N );
ForI: =1 ToNDo
Writeln (random (INF ),'', Random (INF ));
End.
 

Then, write a batch of processes and automatically redirect the input and output of these three programs from the screen navigation keyboard to the file. Then, compare the data generated by standard.exe and overtaking.

 
: Loop
Make.exe> data.txt
Standard.exe <data.txt> std.txt
Overtaking.exe <data.txt> ans.txt
FC std.txt ans.txt
If Errorlevel1Goto End
GotoLoop
: End
 

The command line interface keeps prompting you that you cannot find the file difference, and you can submit it with confidence, provided that your simple algorithm is correct.