题解 | #字符统计#

#include <stdio.h>
#include <string.h>

// a-z
// a-a+10
// 0-9
// 10-35
// 只会出现整数次
//统计最大值后降序输出  max-1

int main()
{
    char str[1001] = {'\0'};
    while (scanf("%s", str) != EOF)
    {
        int count[36] = {0};
        int len = strlen(str);
        for (int i = 0; i < len; i++)
        {
            if (str[i] >= 'a' && str[i] <= 'z')
            {
                count[str[i] - 'a' + 10]++;
            }
            else
            {
                count[str[i] - '0']++;
            }
        }
        int max = 0;
        for (int i = 0; i < 36; i++)
        {
            if (count[i] > max)
                max = count[i];
        }

        for (int i = max; i >= 1; i--)
        {
            for (int j = 0; j < 36; j++)
            {
                if (count[j] == i)
                {
                    if (j >= 0 && j <= 9)
                        printf("%c", j + '0');
                    else
                        printf("%c", j - 10 + 'a');
                }
            }
        }
        printf("\n");
    }

    return 0;
}