[C/C++] 1002 写出这个数 (20)（20 分）

#include<stdio.h> 
#include<string.h>
int main()
{   
    char a[100];
    char ref[10][5] ={"ling","yi","er","san","si","wu","liu","qi","ba","jiu"};
    scanf("%s",a);
    int len = strlen(a);
    int sum = 0;
    for(int i = 0;i<len;i++) {
        sum += (a[i]-'0');
    }
    char s[110];
    int i = 0;
    while(sum != 0){
        s[i]=(sum%10)+'0';
        sum /= 10;
        i++;
    }
    int n = strlen(s);
    for(int i = n-1;i>=0;i--) {
        printf("%s",ref[s[i]-'0']);
        if(i>0) printf(" ");
    }

    return 0;
 }