CodeForces - 363C Fixing Typos （字符串处理）

C. Fixing Typostime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard output

Many modern text editors automatically check the spelling of the user's text. Some editors even suggest how to correct typos.

In this problem your task to implement a small functionality to correct two types of typos in a word. We will assume that three identical letters together is a typo (for example, word "helllo" contains a typo). Besides, a couple of identical letters immediately followed by another couple of identical letters is a typo too (for example, words "helloo" and "wwaatt" contain typos).

Write a code that deletes the minimum number of letters from a word, correcting described typos in the word. You are allowed to delete letters from both ends and from the middle of the word.

Input

The single line of the input contains word s, its length is from 1 to 200000 characters. The given word s consists of lowercase English letters.

Output

Print such word t that it doesn't contain any typos described in the problem statement and is obtained from s by deleting the least number of letters.

If there are multiple solutions, print any of them.

Examplesinput

helloo

output

hello

input

woooooow

output

woow

Note

The second valid answer to the test from the statement is "heloo".

题意：单词需要校对，把错误的改成正确的，错误单词的标准是：      1.有三个连续相同的字母，如www;      2.有多对有两个连续相同的字母，如aammzzdd代码：

#include<stdio.h>
#include<string.h>
int main()
{
    char s1[202000],s2[20200];
    while(~scanf("%s",s1))
    {
        int len=strlen(s1);
        int top=0;
        s2[top++]=s1[0];
        s2[top++]=s1[1];
        for(int i=2 ; i<len ; i++ )
        {
            //当前字母与栈顶字母相同，且栈顶下第一个字母相同（三个连续相同的字母）
            if(s1[i]==s2[top-1]&&s2[top-1]==s2[top-2])
                continue;
            //当前字母与栈顶字母相同，且栈顶下第一个字母与栈顶下第二个字母相同（wwoo这种情况）
            if(s1[i]==s2[top-1]&&s2[top-2]==s2[top-3])
                continue;
            s2[top++]=s1[i];
        }
        s2[top]='\0';//字符数组末尾加'\0';
        printf("%s\n",s2);
    }
    return 0;
}
//不能入栈的两种情况
//1.当前字母与栈顶字母相同，且栈顶下第一个字母相同（三个连续相同的字母）
//2.当前字母与栈顶字母相同，且栈顶下第一个字母与栈顶下第二个字母相同（wwoo这种情况）
//wwaatt--->wwatt
//helloo-->hello  or   heloo