【POJ 3461】 Oulipo

 【题目链接】

             点击打开链接

【算法】

           KMP

【代码】

          

#include <algorithm>
#include <bitset>
#include <cctype>
#include <cerrno>
#include <clocale>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <limits>
#include <list>
#include <map>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <utility>
#include <vector>
#include <cwchar>
#include <cwctype>
#include <stack>
#include <limits.h>
using namespace std;
#define MAXW 10010
#define MAXT 1000010

int T,l1,l2;
char s1[MAXW],s2[MAXT];
int next[MAXW];

template <typename T> inline void read(T &x) {
        int f = 1; x = 0;
        char c = getchar();
        for (; !isdigit(c); c = getchar()) { if (c == '-') f = -f; }
        for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0';
        x *= f;
}

template <typename T> inline void write(T x) {
    if (x < 0) { putchar('-'); x = -x; }
    if (x > 9) write(x/10);
    putchar(x%10+'0');
}

template <typename T> inline void writeln(T x) {
    write(x);
    puts("");
}

inline void getnext() {
        int i,pos;    
        next[1] = 0;
        for (i = 2; i <= l1; i++) {
                pos = next[i-1];
                while (pos > 0 && s1[pos+1] != s1[i]) pos = next[pos];
                if (s1[pos+1] == s1[i]) next[i] = pos + 1;
                else next[i] = 0;
        }
}

inline void kmp() {
        int i,pos=0,sum=0;
        for (i = 1; i <= l2; i++) {
                while (pos > 0 && s2[i] != s1[pos+1]) pos = next[pos];
                if (s2[i] == s1[pos+1]) pos++;
                else pos = 0;
                if (pos == l1) sum++;
        }    
        writeln(sum);
}

int main() {
        
        read(T);
        while (T--) {
                scanf("%s%s",s1+1,s2+1);
                l1 = strlen(s1+1); l2 = strlen(s2+1);
                getnext();
                kmp();    
        }
        
        return 0;
    
}