题解 | #字符统计#

#include <stdio.h>
#include<string.h>
#define   N   1000

int main() {
    char c[N], tmp;
    int dp[N]={0}, i = 0, j = 0, k = 0, len,cnt=0;
    scanf("%s",c);
    len = strlen(c);
    for (i = 0; i < len; i++) {
        
        for (j = i; j < len+1; j++) {
            if (c[j] == c[i]) {
                dp[i]++;
                if (dp[i] != 1) {
                    for (k = j; k < len; k++) {
                        c[k] = c[k + 1]; //所有元素前移
                    }
                    j--;
                    len = len - 1;
                }
            }
        }
    }
    k = 0;
    //冒泡排序
    for(i=0;i<=len;i++) {
        for (j = 0; j <= len; j++) {
            if (dp[j] < dp[j + 1]) {
                tmp = c[j];
                c[j] = c[j + 1];
                c[j + 1] = tmp;
                //交换字符位置
                k = dp[j];
                dp[j] = dp[j + 1];
                dp[j + 1] = k;
                //交换统计数量位置

            }
        }
    }
    //再次冒泡排序排列相同出现次数字符
    for (i = 0; i < len; i++) {
        for (j = 0; j <= len; j++) {
            if (dp[j] == dp[j + 1]) {
                if (c[j] > c[j + 1]) {
                    tmp = c[j];
                    c[j] = c[j + 1];
                    c[j + 1] = tmp;
                }
            }
        }
    }

    for (i = 0; i < len; i++) {
        printf("%c", c[i]);
    }

    return 0;
}