pta basic level 1002

#include<stdio.h>
#include<math.h>

void Switch_n(int a)
{
    switch(a)
    {
        case 0:printf( "ling");break;
        case 1:printf( "yi");break;
        case 2:printf("er");break；
        case 3:printf( "san");break;
        case 4:printf( "si");break;
        case 5:printf( "wu");break;
        case 6:printf( "liu");break;
        case 7:printf( "qi");break;
        case 8:printf( "ba");break;
        case 9:printf( "jiu");break;
        default:break;
    }
}
int main()
{
    char m[101];
    int sum[100],x=0,n=0,i=0;
    scanf("%s",m);
    while(m[i]!='\0')
    {
        x=x+m[i]-'0';
        i++;
    }
    if(x==0) sum[0]=0,n=1;
    while(x>0)
    {
        sum[n]=x%10;
        x=x/10;
        n++;
    }
    for(i=n-1;i>-1;i--)
    {
        Switch_n(sum[i]);
        if(i!=0) printf(" ");
    }
    return 0;
}