In a game,Children is requested to take S (1＜=S＜N) digits fr

In a game,Children is requested to take S (1＜=S＜N) digits from a big number which has N digits (1＜N＜240),when they have taken all the S digits form the number ,all the digits left should be the most minimum if the order of the digits left is not changed.Please write a program to help him.
Input
Input includes n test cases.Each line contains one case with two numbers.First one of it is the number to be taken; the second is the number of digits the children should take.
Output
Output the minimum number left for each case.
Sample Input
1458734 3
2324876 4
Sample Output
1434
224
我的代码：
#include
#include
using namespace std;
int main()
{
int i,j,h,n,index,count;
char ch,a[240];
while(cin>>a>>n)
{
h=strlen(a); // 可能有0
count=h-n;
index=-1;
for(j=0;j