[模板]KMP
很早之前學(xué)的KMP因?yàn)闆]大用過一直不理解原理,今天訓(xùn)練賽做到一個(gè)基本裸的沒打出來,于是上網(wǎng)又搜了一些資料看,大致理解了原理,打了個(gè)相對(duì)簡(jiǎn)單的板子。
這東西還是挺好用的,最近要專門訓(xùn)練一下字符串的題。
#include <bits/stdc++.h>using namespace std;typedef long long int LL;#define st first #define nd second #define pb push_back #define mp make_pair #define pll pair <LL, LL> #define pii pair <int, int> #define rep(i,x) for(int i=1;i<=x;i++)const int N = 2e6+7; const int MX = 1e9+7; const LL INF = 1e18+9LL;string s,a,b;int nxt[N];//最長相等前后綴長度-1void getnext(string s){nxt[0] = -1;int k = -1;for (int q = 1; q < s.size(); q++){while (k > -1 && s[k + 1] != s[q]){k = nxt[k];}if (s[k + 1] == s[q]){k++;}nxt[q] = k;} }void kmp(string s,string p){int k=-1;for(int i=0;i<s.size();i++){while(k>-1&&p[k+1]!=s[i]){k=nxt[k];}if(p[k+1]==s[i]){k++;}if(k==int(p.size())-1){cout<<i+2-int(p.size())<<endl;i=i+1-int(p.size());k=-1;}}}int main(){string s1,s2;cin>>s1>>s2;getnext(s2);kmp(s1,s2); }?
轉(zhuǎn)載于:https://www.cnblogs.com/xutianshu/p/10182305.html
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