VK Cup 2012 Qualification Round 2 C. String Manipulation 1.0

C. String Manipulation 1.0

time limit per test

3 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

One popular website developed an unusual username editing procedure. One can change the username only by deleting some characters from it: to change the current name s, a user can pick number p and character c and delete the p-th occurrence of character c from the name. After the user changed his name, he can't undo the change.

For example, one can change name "arca" by removing the second occurrence of character "a" to get "arc".

Polycarpus learned that some user initially registered under nickname t, where t is a concatenation of k copies of string s. Also, Polycarpus knows the sequence of this user's name changes. Help Polycarpus figure out the user's final name.

<p< p="" style="color: rgb(34, 34, 34); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; line-height: 21px; "><p< p="">

Input

<p< p="">

The first line contains an integer k (1 ≤ k ≤ 2000). The second line contains a non-empty string s, consisting of lowercase Latin letters, at most 100 characters long. The third line contains an integer n (0 ≤ n ≤ 20000) — the number of username changes. Each of the next n lines contains the actual changes, one per line. The changes are written as "p_i c_i" (without the quotes), where p_i (1 ≤ p_i ≤ 200000) is the number of occurrences of letter c_i, c_i is a lowercase Latin letter. It is guaranteed that the operations are correct, that is, the letter to be deleted always exists, and after all operations not all letters are deleted from the name. The letters' occurrences are numbered starting from 1.

<p< p=""><p< p="">

Output

<p< p="">

Print a single string — the user's final name after all changes are applied to it.

<p< p=""><p< p="">

Sample test(s)

<p< p=""><p< p="">

input

2bac32 a1 b2 c

output

acb

input

1abacaba41 a1 a1 c2 b

output

baa

<p< p=""><p< p="">

Note

<p< p="">

Let's consider the first sample. Initially we have name "bacbac"; the first operation transforms it into "bacbc", the second one — to "acbc", and finally, the third one transforms it into "acb".

其实就是个水题。。但是比赛的时候没想到直接用一个数组存放用过的点，

关键是用vector对需要删除的点删除

下面是AC代码：

#include <iostream>#include <string>#include <vector>using namespace std;bool checked[200005];vector<int> occ[26];int main(){int K, N;string os, s = "";cin >> K >> os >> N;for (int i = 0; i < K; i++)s += os;for (int i = 0; i < s.size(); i++) occ[((int) s[i])-97].push_back(i);for (int i = 0; i < N; i++) {int oc, in;char c;cin >> oc >> c;in = ((int) c);checked[occ[in-97][oc-1]] = 1;occ[in-97].erase(occ[in-97].begin()+oc-1);}for (int i = 0; i < s.size(); i++)if (!checked[i]) cout << s[i];cout << endl;}