我的手上有一个非常简单的Ada项目。任务是收集“选民”的投票并将其与每个“候选人”的得分进行比较,并确定哪个候选人最适合选民。
输入如下所示,然后输出应该输出:
Input:
0 0 0 1 1 1 -1 -1 -1 1
7
A
1 1 1 1 1 1 1 1 1 1
B
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1
C
1 -1 1 -1 1 -1 1 -1 1 -1
D
1 0 1 0 1 0 1 0 1 0
E
0 -1 0 -1 0 -1 0 -1 0 -1
F
1 1 1 1 0 0 0 0 0 0
G
0 0 0 1 -1 0 0 -1 1 1
Output:
A
F
G
到目前为止,我有一个程序会接受每位候选人的投票,并将其与选民的投票进行比较。我知道我需要做什么,因为我以前用Java做过,但我不知道如何在Ada中接受输入。这是我到目前为止所拥有的。
with Ada.Text_IO, Ada.Integer_Text_IO;
use Ada.Text_IO, Ada.Integer_Text_IO;
procedure Candidates is
-- take an array of candidates and determine which candidate best matches
-- the user's votes, then return those candidates
Number_Of_Candidates: Integer;
subtype VoterArray_Index is Integer range 1..10;
subtype CandidatesArray_Index is Integer range 1..Number_Of_Candidates;
type VoterArray is array(VoterArray_Index) of Integer;
type CandidatesArray is array(Character range 'A' .. 'Z') of array;
type Best_CandidatesArray is array(CandidatesArray_Index) of array;
Voter: VoterArray;
Candidates: CandidatesArray;
Best_Candidates: Best_CandidatesArray;
function Get_Input() is
-- get the input and put it into the correct arrays
Current_Line : string;
begin
Get(Current_Line);
function Get_Best_Score(CandidatesArray: in out CandidatesArray) is
-- go through the arrays and find the best score
SameAnswers: Integer;
DifferentAnswers: Integer;
BestScore: Integer;
subtype CandidateArray is array(VoterArray_Index) of Integer;
Candidate: CandidateArray;
begin
for I in CandidatesArray_Index loop
Candidate := Candidates(I);
for J in VoterArray_Index loop
if Candidate(J) /= 0 and Voter(J) /= 0 then
if Candidate(J) /= Voter(J) then
DifferentAnswers := DifferentAnswers + 1
else
SameAnswers := SameAnswers + 1
end if;
end if;
end loop;
if SameAnswers - DifferentAnswers >= BestScore then
Best_Candidates(I) := Candidate;
end if;
SameAnswers := 0;
DifferentAnswers := 0;
end loop;
end Get_Best_Score;
正如您所看到的,我不确定如何获取数字并将它们放入数组中。如果你有任何建议或不同的方式我应该做的事情,我都听见了。
提前致谢。
答案 0 :(得分:3)
您可以使用流来读取数据:
Integer'Read( STREAM_HANDLE, VARIABLE )
另一种选择是通过Get为数组的每个元素读取值,我建议使用辅助函数,以防需要调整处理格式更改的过程:
Function Get_Vote ( File : File_Type ) Return Integer is
begin
Return Result : Integer do
Integer_IO.Get(
File => File,
Item => Result
);
End return;
end Read_Votes;
和
For Index in VOTE_ARRAY'range loop
VOTE_ARRAY( Index ) := Get_Vote( INPUT_FILE );
End loop;
答案 1 :(得分:1)
因为文件中给出了行数,所以constrained array必须足够大以容纳所有可能的元素。相反,您可以声明unconstrained array:
subtype Voter_Index is Positive range 1 .. 10;
type Voter_Array is array(Voter_Index) of Integer;
type Candidate_Array is array(Character range <>) of Voter_Array;
稍后,当您知道实际计数时,您只能分配数组实际需要的空间。该声明将Candidates
放在nested scope:
Number_Of_Candidates := ...;
declare
Candidates : Candidate_Array(
'A' .. Character'Val(Character'Pos('A') + Number_Of_Candidates));
begin
...
end;
或者,你可以allocate space on the heap:
type Candidate_Array_Ptr is access Candidate_Array;
Candidates: Candidate_Array_Ptr;
begin
Number_Of_Candidates := ...;
Candidates := new Candidate_Array(
'A' .. Character'Val(Character'Pos('A') + Number_Of_Candidates));
end;
在任何一种情况下,您都可以根据需要访问数组元素:
for i in Candidates'Range loop
for j in Voter_Array'Range loop
Ada.Integer_Text_IO.put(Candidates(i)(j), 5);
end loop;
Ada.Text_IO.New_Line;
end loop;
附录:此方法假设候选人姓名是连续的Character
。作为替代方案,请考虑一个Candidate_Record
数组,其中从文件中读取每个Name
:
type Candidate_Record is
record
Name : Character;
Votes : Voter_Array;
end record;
type Candidate_Array is array(Positive range <>) of Candidate_Record;
Candidates : Candidate_Array(1 .. Number_Of_Candidates);
for i in Candidates'Range loop
Ada.Text_IO.Put(Candidates(i).Name & ':');
for j in Voter_Array'Range loop
Ada.Integer_Text_IO.Put(Candidates(i).Votes(j), 5);
end loop;
Ada.Text_IO.New_Line;
end loop;