#include<iostream>
#include<stdio.h>
#include<bits/stdc++.h>
#include<cmath>
#include <stdlib.h>
using namespace std;
typedef long long LL;

namespace IO
{
    template<typename T>void write(T x)
    {
        if(x<0)
        {
            putchar('-');
            x=-x;
        }
        if(x>9) write(x/10);
        putchar(x%10+'0');
    }

    template<typename T> void read(T &x)
    {
        x = 0;char ch = getchar();int f = 1;
        while(!isdigit(ch)){if(ch == '-')f*=-1;ch=getchar();}
        while(isdigit(ch)){x = x*10+(ch-'0');ch=getchar();}x*=f;
    }
};
using namespace IO;
vector<char> num; 
char c;
signed main()
{
	LL n,t;
	LL pos=0;
	read(n);read(t);
	num.clear();
	for (LL i=0;i<n;i++){
		cin>>c;
		num.push_back(c);
	}
	
	for (LL i=0;i<n;i++){
		if ((num[i]>='5'&&num[i]<='9')) {
			t--;
			pos=i;
			goto ii;
		}
	}
	
	for (LL i=0;i<n;i++)
	cout<<num[i];
	return 0;
	
	ii: num[pos]=0;
		num[pos-1]++;
		for (LL i=0;i<pos;i++)
		cout<<num[i];
		return 0;
} 

显示
运行错误:请检查是否存在数组、列表等越界非法访问，内存非法访问等情况
double free or corruption (out)