顺序表非零元素向前排，零元素后置

void sort(int *num, int length){
    int j = 0;
    int count = 0;
    for(int i = 0; i < length; i++){
        if(num[i] != 0){
            num[j++] = num[i];
        }else{
            count++;
        }
    }
    for(int k = length - count; k < length; k++){
        num[k] = 0;
    }
}
int main() {
    int a[] = {1,2,3,0,4,0,5,10,9};
    sort(a,9);
    return 0;
}