Submission #1172612

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Source Code Expand

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

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

#define INF (1<<29)
#define INFL (1ll<<60)
#define EPS (1e-8)
#define PI (acos(-1))
const ll MOD = 1000000007ll;

int main() {
	string S;
	int K;
	cin >> S >> K;
	
	assert(S.size() <= 1000);
	
	int c = count(ALL(S), 'a');
	
	vector<string> ans;
	if (S.size() - c <= K) {
		string tmp = "";
		REP(i, S.size() - K) tmp += "a";
		ans.push_back(tmp);
	}
	
	REP(i, 26) {
		string now = S;
		int cnt = 0, pos = -1;
		REP(j, now.size()) {
			if (now[j] == 'a' + i) {
				if (cnt < K) pos = j;
				break;
			}
			
			if (cnt < K && now[j] != 'a') {
				now[j] = 'a';
				cnt++;
			}
		}
		
		string tmp = "";
		while (cnt < K) tmp += "a", cnt++;
		ans.push_back(tmp + now);
		
		if (pos != -1) {
			now[pos] = 'a';
			if (tmp.size() > 0) tmp.erase(tmp.end() - 1);
			ans.push_back(tmp + now);
		}
	}
	
	sort(ALL(ans));
	cout << ans[0] << endl;
	
	return 0;
}

Submission Info

Judge Result