统计输入在字符性质

    题目是这样的：  从输入的一组字符里统计各种字符出现的个数和所占的比例：

#include
#include
#include

int main(void)
{
    int ch;
    int num_cntrl=0;
    int sum=0;
    int num_space = 0;
    int num_digit = 0;
    int num_lower = 0;
    int num_upper = 0;
    int num_other = 0;
    while ( ( ch = getchar() ) != '\n' )
    {
        if ( iscntrl(ch) )      {sum++; num_cntrl++;}
        else if ( isspace(ch) ) {sum++; num_space++;}
        else if ( isdigit(ch) ) {sum++; num_digit++;}
        else if ( islower(ch) ) {sum++; num_lower++;}
        else if ( isupper(ch) ) {sum++; num_upper++;}
        else { num_other++; sum++; }
        }

    printf("total input strigs : %d\n",sum);
    float sum_f = (float)sum;
    printf("cntrl string: %d , %.2f%%\n",num_cntrl,num_cntrl/sum_f*100);
    printf("space string: %d , %.2f%%\n",num_space,num_space/sum_f*100);
    printf("digit string: %d , %.2f%%\n",num_digit,num_digit/sum_f*100);
    printf("lower string: %d , %.2f%%\n",num_lower,num_lower/sum_f*100);
    printf("upper string: %d , %.2f%%\n",num_upper,num_upper/sum_f*100);
    printf("other string: %d , %.2f%%\n",num_other,num_other/sum_f*100);

    }

    今天看的要字符串，这个小程序主要是学习ctype.h里在几个函数在用法。