C语言与汇编的嵌入式编程：统计字符串中各字符出现的次数

#include<stdio.h>
void main(){

    char str[1024];
    char pipei[] = "abcdefghijklmnopqrstuvwxyz";
    int  count[26]={0};
    int i=0,j=0;

    scanf("%s",str);
    printf("%s\n",str);
    
    for(i=0;i<1024;i++)
    {
        for(j=0;j<26;j++)
        {
            if(str[i]==pipei[j])
                count[j]+=1;
        }
    }

    for(j=0;j<26;j++)
    {
        if(count[j]>0)
            printf("%c=%d\n",pipei[j],count[j]);
    }
}

#include<stdio.h>
void main(){

    char str[1024];
    char pipei[] = "abcdefghijklmnopqrstuvwxyz";
    int  count[26]={0};
    int i=0,j=0;

    scanf("%s",str);
    printf("%s\n",str);

    //外层循环start
    _asm{
        mov eax,0    //i=0
        mov ecx,1024    //i<1024
        loop1:
        mov i,eax
        push eax
        push ecx
    };
    //printf("%c\t",str[i]);

    
    //内层循环start
    _asm{
        mov eax,0
        mov ecx,26
        loop2:    
        mov j,eax
        push eax
        push ecx
    };

    if(str[i]==pipei[j])
    {
        count[j]+=1;
    }

    //内循环end
    __asm{
        pop ecx
        pop eax
        add eax,1
        loop loop2    
    };
    

    //外循环end
    _asm{
        pop ecx
        pop eax
        add eax,1
        loop loop1
    };

    
    //输出统计个数
    //外层循环start
    _asm{
        mov eax,0    //i=0
        mov ecx,26    //i<26
        loop3:
        mov j,eax
        push eax
        push ecx
    };
    
    if(count[j]>0)
        printf("%c=%d\n",pipei[j],count[j]);

    //外循环end
    _asm{
        pop ecx
        pop eax
        add eax,1
        loop loop3
    };

}

#include<stdio.h>
void main(){

    char str[1024];
    char temp;
    char pipei[] = "abcdefghijklmnopqrstuvwxyz";
    int  count[26]={0};
    int i=0,j=0;

    char *str1 = "i=%d\n";
    char *str2 = "%c\t";

    scanf("%s",str);
    printf("%s\n",str);

    //temp = str[0];

    printf(str2,str[i]);
    //汇编代码如下
    //mov     edx, dword ptr [ebp-48C]        edx=0
    //movsx   eax, byte ptr [ebp+edx-400]        eax=64h
    //push    eax
    //mov     ecx, dword ptr [ebp-498]        //str2    
    //push    ecx                              ; "%c"
    //call    printf                           ; \printf
    //add     esp, 8
    // ==
    //mov     edx, i
    //movsx    eax,str[edx]
    //push    eax
    //mov        ecx,str2
    //push    ecx
    //call    printf
    //add        esp,8
    
    _asm{
            mov        i,0
start_1024:    nop
            mov        eax,i
            add        eax,1
            mov        i,eax

            cmp        i,10            //    if i<10
            jge        end_1024        

            //逐个输出    printf(str2,str[i]);
            mov     edx, i
            movsx    eax,str[edx]
            push    eax
            mov        ecx,str2
            push    ecx
            call    printf
            add        esp,8

            jmp        start_1024

end_1024:    nop

    
    }
    


}