在洛谷上只得了14分，求助！

#include <bits/stdc++.h>
using namespace std;

int k, sum2 = 0, sum1 = 0, s1;
string n;


int main () {
    cin >> n >> k;
    const int l = n. length ();
	int n1[l];
    for (int i = 0; i < l; i ++)
        n1[i] = n[i] - '0';
        
    while (k) {
    	int sss;
        sum1 = n1[0];
        sum2 = 0, s1 = -1;
        for (int i = 1; i < l; i ++) {
        	if (n1[i] != -1) {
            	if (n1[i] > sum1) {
            	    if ((sum2 == 1 || sum2 == 2) && k != 0)
            	        k --, n1[s1] = -1, sum2 = 10;
            
            	    else
            	        sum2 = 10;
            	}   
            

            	else if (n1[i] < sum1) {
            	    if (sum2 == 10 && k != 0) 				
            	        k --, n1[i - 1] = -1, sum2 = 1, s1 = i;
                
            	    else if (sum2 == 1)
            	        sum2 = 2;
            
            	    else if (sum2 == 0)
            	        sum2 = 1, s1 = i - 1;
            	}
            	sum1 = n1[i], sss = i;
            }
        }
        if (k != 0)
            {k --; n1[sss] = -1;}
    }
    
    for (int i = 0; i < l; i ++)
        if (n1[i] != -1)
            cout << n1[i];
    
    return 0;
}