[题意] 给出一个字符串,求出最小周期. [思路] 对KMP的next数组的理解与运用orz ①证明:如果最小周期不等于它本身,则前缀和后缀必定有交叉. 如果没有交叉,以当前的next[n]为最小周期, 中间部分可能会小于next[n](无解),或者中间可能由若干个前缀组成,此时next[n]会变大,舍去! ----------------------- ----------------------- ②证明:假设满足了n%(n-next[i])==0,那么n-next[i]是周期 这部分证明直…

题目链接:https://vjudge.net/problem/POJ-2406 Power Strings Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 52631   Accepted: 21921 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc"…

poj2406 Power Strings(kmp) 给出一个字符串,问这个字符串是一个字符串重复几次.要求最大化重复次数. 若当前字符串为S,用kmp匹配'\0'+S和S即可. #include <cstdio> #include <cstring> using namespace std; const int maxn=2e6+5; char s1[maxn], s2[maxn]; int n1, n2, nxt[maxn], ans; int main(){ while (~…

题意 求所有循环次数大于1的前缀 的最大循环次数和前缀位置 解法 直接用KMP求最小循环节 当满足i%(i-next[i])&&next[i]!=0 前缀循环次数大于1 最小循环节是i-next[i] #include <cstdio> #include <cstring> #include <iostream> #include <cstdlib> using namespace std; char S[2000000]; int NEXT…

Power Strings   Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 47748   Accepted: 19902 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = &quo…

E - Power Strings Time Limit:3000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice POJ 2406 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = &…

Power Strings Problem's Link: http://poj.org/problem?id=2406 Mean: 给你一个字符串,让你求这个字符串最多能够被表示成最小循环节重复多少次得到. analyse: KMP之next数组的运用.裸的求最小循环节. Time complexity: O(N) Source code:  ;;      ;);      ) ;}/* */…

Power Strings Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 39291 Accepted: 16315 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "abcd…

Power Strings Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 33178   Accepted: 13792 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "…

Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "abcdef". If we think of concatenation as multiplication, exponentiation by a non-negative integer is defin…