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当我搜索数组前 1/4 范围内的数字时，我不断收到错误消息。例如，任何超过 76 的数字都不可搜索。另外，任何低于我在数组中的最小数字或高于我的最高数字的数字也是不可能的。有什么建议么？

我尝试了很多次在记忆之间切换，但仍然没有用。

program BinarySearch;

#include("stdlib.hhf")                                                          

const ArraySize := 17;                                                          

static
    SortedData: uns32 [ArraySize] := [ 15, 20, 25, 30, 35, 40, 45, 50,          
                                     55, 60, 65, 70, 75, 80, 85, 90, 95 ];
    found:      boolean := false;                                               
    searchItem: uns32;                                                          

begin BinarySearch;

    stdout.put(nl, "Enter a two-digit number for search: ");                    
    stdin.get(searchItem);

    mov(0, ecx);                                                                
    mov(ArraySize - 1, eax);
    while(ecx <= eax && found == false) do                                      

        add(ecx, eax);
        mov(eax, ebx);
        mov(0, edx);
        div(2, edx:eax);                                                        
        mov(eax, edx);
        mov(ebx, eax);
        mov(edx, ebx);
        mov(searchItem, edx);

        if(edx < SortedData[ebx * 4]) then                                      
            sub(1, ebx);
            mov(ebx, eax);
        elseif(edx > SortedData[ebx * 4]) then                                  
            add(1, ebx);
            mov(ebx, ecx);
        else
            mov(true, found);                                                   
        endif;

    endwhile;

    stdout.put(nl, "Binary Search : ", nl);
    for(mov(0, ecx); ecx < ArraySize; inc(ecx)) do                              
        stdout.puti32Size(SortedData[ecx * 4], 4, ' ');
    endfor;
    stdout.newln();                                                             

    if(found) then                                                              
        stdout.put("Found, Search item: ", searchItem, nl);
    else
        stdout.put("Not Found, Search item: ", searchItem, nl);
    endif;

end BinarySearch;
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1 回答 1

0

环境

  • HLA (High Level Assembler - HLABE back end, POLINK linker) 版本 2.16 build 4413 (prototype)
  • 视窗 10

解决方案

将storedData数组的声明/初始化从移动static到readonly将解决访问数组较高索引时的内存访问冲突。

改变：

static
    sortedData: uns32 [ArraySize] := [ 15, 20, 25, 30, 35, 40, 45, 50,          
                                     55, 60, 65, 70, 75, 80, 85, 90, 95 ];
    found:      boolean := false;                                               
    searchItem: uns32;

至：

static
    found:      boolean := false;                                               
    searchItem: uns32;                                                          

readonly
    sortedData: uns32 [ArraySize] := [ 15, 20, 25, 30, 35, 40, 45, 50,          
                                     55, 60, 65, 70, 75, 80, 85, 90, 95 ];

在 while 循环中添加一个附加条件EAX > -1将纠正在搜索小于sortedData.

改变：

while(ecx <= eax && found == false) do

至：

while(ecx <= eax && found == false && eax > -1) do

例子

这个例子也考虑了之前关于这个问题的一些评论。

program BinarySearch;
#include("stdlib.hhf");

const
    ArraySize:= 17;

readonly
    SortedData: uns32 [ArraySize]:= 
        [15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95];

begin BinarySearch;
    stdout.put(nl, "Enter a two-digit number for search: ");                    
    stdin.getu32();

    mov(EAX, EDI);
    xor(ECX, ECX);                                                                
    mov(ArraySize, EAX);
    while(ECX <= EAX && EAX > -1) do                                      

        add(ECX, EAX);
        mov(EAX, ESI);
        shr(1, EAX);                                                        
        mov(EAX, EBX);
        mov(ESI, EAX);

        if(EDI < SortedData[EBX * 4]) then                                      
            dec(EBX);
            mov(EBX, EAX);
        elseif(EDI > SortedData[EBX * 4]) then                                  
            inc(EBX);
            mov(EBX, ECX);
        else
            xor(EBX, EBX);  
            break;                                                 
        endif;

    endwhile;

    stdout.put(nl, "Binary Search: ", nl);
    for(mov(0, ECX); ECX < ArraySize; inc(ECX)) do                              
        stdout.puti32Size(SortedData[ECX * 4], 4, ' ');
    endfor;

    if(EBX) then                                                              
        stdout.put(nl, "Not Found, Search item: ", (type uns32 EDI), nl);
    else
        stdout.put(nl, "Found, Search item: ", (type uns32 EDI), nl);
    endif;

end BinarySearch;
于 2020-06-13T18:38:45.607 回答