Oulipo

链接：http://acm.hust.edu.cn/vjudge/problem/10368/origin

题目：

The French author Georges Perec (1936–1982) once wrote a book, La disparition, without the letter'e'. He was a member of the Oulipo group. A quote from the book:

Tout avait Pair normal, mais tout s’affirmait faux. Tout avait Fair normal, d’abord, puis surgissait l’inhumain, l’affolant. Il aurait voulu savoir où s’articulait l’association qui l’unissait au roman : stir son tapis, assaillant à tout instant son imagination, l’intuition d’un tabou, la vision d’un mal obscur, d’un quoi vacant, d’un non-dit : la vision, l’avision d’un oubli commandant tout, où s’abolissait la raison : tout avait l’air normal mais…

Perec would probably have scored high (or rather, low) in the following contest. People are asked to write a perhaps even meaningful text on some subject with as few occurrences of a given “word” as possible. Our task is to provide the jury with a program that counts these occurrences, in order to obtain a ranking of the competitors. These competitors often write very long texts with nonsense meaning; a sequence of 500,000 consecutive'T's is not unusual. And they never use spaces.

So we want to quickly find out how often a word, i.e., a given string, occurs in a text. More formally: given the alphabet {'A','B', 'C', …, 'Z'} and two finite strings over that alphabet, a wordW and a text T, count the number of occurrences of W inT. All the consecutive characters of W must exactly match consecutive characters ofT. Occurrences may overlap.

题意：有两个字符串，问a串在b串种出现了几次。

分析：简单的kmp题。代板子就行了

题解：

#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <queue>#include <stack>#include <vector>#include <map>#include <string>#include <cstring>#include <functional>#include <cmath>#include <cctype>#include <cfloat>#include <climits>#include <complex>#include <deque>#include <list>#include <set>#include <utility>#define rt return 0#define fr freopen("in.txt","r",stdin)#define fw freopen("out.txt","w",stdout)#define ll long long#define detie ios_base::sync_with_stdio(false);cin.tie(false)using namespace std;int Next[1000010];void getNext(string s){int j = 0;int k = -1;Next[0] = -1;while (j<s.size()){if (k == -1 || s[j] == s[k])Next[++j] = ++k;elsek = Next[k];}}int KMP_Count(string a, string b){int sum = 0;int i = 0;int j = 0;getNext(b);while (i < a.size()){if (j == -1 || a[i] == b[j]){i++;j++;}elsej = Next[j];if (j == b.size()){sum++;}}return sum;}int main(){//fr;detie;int n;cin >> n;while (n--){string a, b;cin >> a >> b;cout << KMP_Count(b, a) << endl;}rt;}