Codeforces 888C：K-Dominant Character

题目链接

K-Dominant Character

Time limit:2 seconds Memory limit:256 megabytes

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Problem Description

You are given a string s consisting of lowercase Latin letters. Character c is called k-dominant iff each substring of s with length at least k contains this character c.

You have to find minimum k such that there exists at least one k-dominant character.

Input

The first line contains string s consisting of lowercase Latin letters (1 ≤ |s| ≤ 100000).

Output

Print one number — the minimum value of k such that there exists at least one k-dominant character.

Examples

input
abacaba
output
2

input
zzzzz
output
1

input
abcde
output
3

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题意：

给出一个字母串，k满足：长度至少为k的字串一定包含某字母c，求最小的k

解题思路：

一个数组记录每个字母上一次出现的位置，用来计算另一个数组：记录每个字母与其相邻的相同字母的最大距离（设0和len两个位置一定有相同的字母），答案就是这个数组中的最小值啦~

Code：

#include <cstdio>#include <iostream>#include <cstring>#include <map>using namespace std;const int maxn=100000+5;char s[maxn];int last[50];int dis[50];int main(){    scanf("%s",s);    memset(last,-1,sizeof(last));    int len=strlen(s);    for(int i=0; i<len; i++)    {        int c=s[i]-'a';        dis[c]=max(dis[c],i-last[c]);        last[c]=i;    }    for(int i=0; i<26; i++)        dis[i]=max(dis[i],len-last[i]);    int ans=len;    for(int i=0; i<26; i++)    {        //cout<<dis[i]<<' ';        ans=min(ans,dis[i]);    }    printf("%d\n",ans);    return 0;}