程序代码：

#include <stdio.h>

int  main()
{
    struct Count
    {
        int c;
        int count;
    };
    struct Count counter[256];
    int i=0;
    for(i=0;i<256;i++) {counter[i].c=i;counter[i].count=0;}
    FILE* fp;
    fp=fopen("d:\\b.txt","r");
    char flag=0xA;
    int lines=0;
    char tline[256]={'\0'};
    char* cp=tline;
    char tmp;
    while(!feof(fp))
    {
        tmp=getc(fp);
        counter[tmp].count++;
    }
    //sort
    int m,n,tmp2,tmp3;
    for(m=0;m<256;m++)
    {
        for(n=m+1;n<256;n++)
        {
            if(counter[m].count>=counter[n].count)
            {
                tmp2=counter[m].count;
                counter[m].count=counter[n].count;
                counter[n].count=tmp2;
                tmp3=counter[m].c;
                counter[m].c=counter[n].c;
                counter[n].c=tmp3;
            }
        }
    }
    //sort end
    int _chars=0;
    for(i=0;i<256;i++)
    {
        if(counter[i].count>0)
        {
            _chars+=counter[i].count;
            if(counter[i].c==0xA)   //\n
            {
                printf("\\n  Number of occurrences=%d\n",counter[i].count);
            }
            else
                if(counter[i].c==0x20)  //space
                {
                    printf("space Number of occurrences=%d\n",counter[i].count);
                }
                else
                    if(counter[i].c==0x9)  //\t
                    {
                        printf("\\t  Number of occurrences=%d\n",counter[i].count);
                    }
                    else
                        if(counter[i].c==0x0)  //NULL
                        {
                            printf("NULL  Number of occurrences=%d\n",counter[i].count);
                        }
                        else
                            if(counter[i].c==0xD)  //
                            {
                                printf("OxD  Number of occurrences=%d\n",counter[i].count);
                            }
                            else  /*Visible characters*/printf("%c  Number of occurrences=%d\n",counter[i].c,counter[i].count);
        }
    }
    printf("File the total number of characters=%d\n",_chars);
    fclose(fp);
    return 0;
}

/*
w  Number of occurrences=1
V  Number of occurrences=1
O  Number of occurrences=1
I  Number of occurrences=1
E  Number of occurrences=1
:  Number of occurrences=1
9  Number of occurrences=1
1  Number of occurrences=1
#  Number of occurrences=1
!  Number of occurrences=1
g  Number of occurrences=2
U  Number of occurrences=2
F  Number of occurrences=2
D  Number of occurrences=2
C  Number of occurrences=2
A  Number of occurrences=2
'  Number of occurrences=2
_  Number of occurrences=3
>  Number of occurrences=3
3  Number of occurrences=3
*  Number of occurrences=4
L  Number of occurrences=5
<  Number of occurrences=5
6  Number of occurrences=6
5  Number of occurrences=6
x  Number of occurrences=8
N  Number of occurrences=8
%  Number of occurrences=8
b  Number of occurrences=9
2  Number of occurrences=10
d  Number of occurrences=11
h  Number of occurrences=12
,  Number of occurrences=12
+  Number of occurrences=12
}  Number of occurrences=15
{  Number of occurrences=15
l  Number of occurrences=15
a  Number of occurrences=16
\  Number of occurrences=16
/  Number of occurrences=16
0  Number of occurrences=18
"  Number of occurrences=18
)  Number of occurrences=24
(  Number of occurrences=24
p  Number of occurrences=25
s  Number of occurrences=26
m  Number of occurrences=27
]  Number of occurrences=29
[  Number of occurrences=29
.  Number of occurrences=29
f  Number of occurrences=35
=  Number of occurrences=39
;  Number of occurrences=42
\t  Number of occurrences=45
i  Number of occurrences=55
u  Number of occurrences=64
o  Number of occurrences=71
e  Number of occurrences=75
r  Number of occurrences=76
\n  Number of occurrences=78
t  Number of occurrences=90
n  Number of occurrences=94
c  Number of occurrences=95
space Number of occurrences=744
File the total number of characters=2094
*/