我的做法是“加最小的数字”，然而碰到了一些诡异的事情...第一次WA了三个点，我下载了第一个数据，输入是：50074897 2，我的做法下输出应该是500487，但是答案告诉我是4897，然后我就认为0肯定是不算的，所以就有了如下的代码：

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, m, n) for(int i = m; i <= n; i++)
#define per(i, m, n) for(int i = m; i >= n; i--)
const int INF = 0x3f3f3f3f;

string str, s, s2;

void build(int start, int k) {
	int n = s.length();
	// cout << start << endl;
	// cout << k << endl;
	if (k == 0) {
		rep(i, start, n - 1) {
			str += s[i];
		}
		return ;
	}
	int loc, num = 10;
	for (int i = start; i <= start + k; i++) {
		if (s[i] - '0' < num) {
			loc = i;
			num = s[i] - '0';
			if (num == 0) break;
		}
	}
	str += s[loc];
	build(loc + 1, k - (loc - start));
}

int main() {
	ios::sync_with_stdio(false);
	// freopen("input.txt", "r", stdin);
	cin >> s2;
	int n = s2.length();
	rep(i, 0, n - 1) if (s2[i] != '0') {
		s += s2[i];
	}
	// cout << s << endl;
	int k, loc, num = 10;
	cin >> k;
	rep(i, 0, k) {
		if (s[i] - '0' < num && s[i] - '0' != 0) {
			loc = i;
			num = s[i] - '0';
			if (num == 1) break;
		}
	}
	str += s[loc];
	k -= loc;
	build(loc + 1, k);
	cout << str << endl;
    return 0;
}

然后又WA了三个点，下载的数据却告诉我这个：68129545206 6，然后我就很愉快的输出了1226，可是答案却是12206。于是我发现：肯定是在算首位的时候才把零除去的！然后就有了如下的代码：

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, m, n) for(int i = m; i <= n; i++)
#define per(i, m, n) for(int i = m; i >= n; i--)
const int INF = 0x3f3f3f3f;

string str, s;

void build(int start, int k) {
	int n = s.length();
	// cout << start << endl;
	// cout << k << endl;
	if (k == 0) {
		rep(i, start, n - 1) {
			str += s[i];
		}
		return ;
	}
	int loc, num = 10;
	for (int i = start; i <= start + k; i++) {
		if (s[i] - '0' < num) {
			loc = i;
			num = s[i] - '0';
			if (num == 0) break;
		}
	}
	str += s[loc];
	build(loc + 1, k - (loc - start));
}

int main() {
	ios::sync_with_stdio(false);
	// freopen("input.txt", "r", stdin);
	cin >> s;
	// cout << s << endl;
	int k, loc, num = 10, cnt = 0;
	cin >> k;
	rep(i, 0, k) if (s[i] == '0') cnt++;
	rep(i, 0, k + cnt) {
		if (s[i] - '0' < num && s[i] - '0' != 0) {
			loc = i;
			num = s[i] - '0';
			if (num == 1) break;
		}
	}
	str += s[loc];
	k -= loc;
	build(loc + 1, k + cnt);
	cout << str << endl;
    return 0;
}

我自信提交，结果第六个点出现了：On column 2, read 0, expected 1. QWQ 然后第七个点还RE了QWQ