Created
November 13, 2018 09:41
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| /* | |
| * Name: Shift The String | |
| * Created by Dipta Das on 09-11-18 | |
| * Problem Link: https://www.codechef.com/problems/TASHIFT | |
| * solution: https://gist.github.com/dipta10/3b94ced5e21649275087721a09a6e741 | |
| * Editorial: https://discuss.codechef.com/questions/48550/tashift-editorial | |
| */ | |
| #include <bits/stdc++.h> | |
| #include <stdio.h> | |
| #define fin freopen("input", "r", stdin) | |
| using namespace std; | |
| vector<int> constructTempArray(string pattern) { | |
| vector<int> lps(pattern.length()); | |
| int index = 0; | |
| for (int i = 1; i < (int) pattern.length(); ) { | |
| if (pattern[i] == pattern[index]) lps[i] = index + 1, ++index, ++i; | |
| else { | |
| if (index != 0) index = lps[index - 1]; | |
| else lps[i] = index, ++i; | |
| } | |
| } | |
| return lps; | |
| } | |
| int KMPMultipleTimes (string text, string pattern) { | |
| int best = 0, result = 0, ans = 0; | |
| vector<int> lps = constructTempArray(pattern); | |
| int j = 0, i = 0; | |
| // i --> text, j --> pattern | |
| while (i < (int) text.length()) { | |
| if (text[i] == pattern[j]) ++i, ++j, best++; | |
| else { | |
| best = 0; | |
| if (j != 0) j = lps[j - 1]; | |
| else ++i; | |
| } | |
| if (best > result) result = best, ans = i - j; | |
| if (j == (int) pattern.length()) { | |
| break; | |
| } | |
| } | |
| return ans; | |
| } | |
| int main() { | |
| ios_base::sync_with_stdio(false); | |
| cin.tie(NULL); | |
| int n; string a, b; | |
| cin >> n >> a >> b; | |
| b += b; | |
| cout << KMPMultipleTimes(b, a) << endl; | |
| return 0; | |
| } |
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