一道c语言问题

#define N 10 int main() { int i=0,j,k,m,a[N]; long int n; scanf("%ld",&n); while(n>0) {a[i++]=n%10; n/=10;} for(j=1;j<i;j++) for(k=0;k<i-j;k++) if(a[k+1]>a[k]) {m=a[k+1];a[k+1]=a[k];a[k]=m;} for(k=0;k