标签：contest lan may single some ranking one red auth
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 word W and a text T, count the number of occurrences of W in T. All the consecutive characters of W must exactly match consecutive characters of T. Occurrences may overlap.
Input
The first line of the input file contains a single number: the number of test cases to follow. Each test case has the following format:
Output
For every test case in the input file, the output should contain a single number, on a single line: the number of occurrences of the word W in the text T.
Sample Input
3 BAPC BAPC AZA AZAZAZA VERDI AVERDXIVYERDIAN
Sample Output
1 3 0
作为一道kmp的例题放在这里。
int nt[1000005]; string w,t;//w是模式串，t是匹配串 void init(){ memset(nt,0,sizeof(nt)); int l=t.length(),j(-1),i=0; nt[0]=-1; while(i!=l){ if(j==-1||t[i]==t[j]) nt[++i]=++j; else j=nt[j]; } } int kmp(){ int lw(w.length()),lt(t.length()),i=0,j=0,cnt(0); while(i!=lt&&j!=lw){ if(t[i]==w[j]||j==-1) ++i,++j; else j=nt[j]; if(j==lw){ cnt++; j=nt[j]; } } return cnt; }
标签：contest lan may single some ranking one red auth
原文地址：https://www.cnblogs.com/wengsy150943/p/10991212.html
