PAT甲1112字符串

PAT甲1112字符串

题目链接
1112 Stucked Keyboard (20分)
On a broken keyboard, some of the keys are always stucked. So when you type some sentences, the characters corresponding to those keys will appear repeatedly on screen for k times.

Now given a resulting string on screen, you are supposed to list all the possible stucked keys, and the original string.

Notice that there might be some characters that are typed repeatedly. The stucked key will always repeat output for a fixed k times whenever it is pressed. For example, when k=3, from the string thiiis iiisss a teeeeeest we know that the keys i and e might be stucked, but s is not even though it appears repeatedly sometimes. The original string could be this isss a teest.

Input Specification:
Each input file contains one test case. For each case, the 1st line gives a positive integer k (1<k≤100) which is the output repeating times of a stucked key. The 2nd line contains the resulting string on screen, which consists of no more than 1000 characters from {a-z}, {0-9} and _. It is guaranteed that the string is non-empty.

Output Specification:
For each test case, print in one line the possible stucked keys, in the order of being detected. Make sure that each key is printed once only. Then in the next line print the original string. It is guaranteed that there is at least one stucked key.

Sample Input:
3
caseee1__thiiis_iiisss_a_teeeeeest
Sample Output:
ei
case1__this_isss_a_teest

题意：
键盘某些键卡住了，按一次重复k次，要求找出可能的键，并且输出（输入的）正确的字符串顺序。可能的键按照被发现的顺序输出。

题解：
hash表存储是否是坏键。如果是坏键的话，每次会出现k次，将它标注上，然后跳过cnt个字符继续进行判断，将所有的坏键找出。然后将坏键按照发现的顺序输出，输出过的将不再输出。最后输出正确的输入。。。

代码：

#include<bits/stdc++.h>
using namespace std;
int main()
{
	string input,output="";
	int k;
	cin>>k>>input;
	int hashTable[128]={0},isout[128]={0};
	
	for(int i=0;i<input.size();)
	{
		int cnt=1;
		for(int j=i+1;j<input.size()&&input[j]==input[i];j++)
			cnt++;
		if(cnt%k!=0)
			hashTable[input[i]]=1;
		i+=cnt;
	}
	
	for(int i=0;i<input.size();i++)
	{
		if(!hashTable[input[i]] && !isout[input[i]]){
			cout<<input[i];
			isout[input[i]]=1;
		}
	}
	
	cout<<endl;
	for(int i=0;i<input.size();)
	{
		cout<<input[i];
		if(!hashTable[input[i]])
			i+=k;
		else
			i+=1;
	}
	return 0;
}