POJ 3461 Oulipo(简单KMP)

解题思路：

典型KMP，直接搞。

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <queue>
#include <stack>
#define LL long long
#define FOR(i,x,y) for(int i=x;i<=y;i++)
using namespace std;
const int maxn = 1000000 + 10;
char s[maxn], t[maxn];
int next[maxn];
void get_next()
{
    int m = strlen(s);
    next[0] = 0; next[1] = 0;
    for(int i=1;i<m;i++)
    {
        int j = next[i];
        while(j && s[i] != s[j]) j = next[j];
        next[i+1] = (s[i] == s[j]) ? j + 1: 0;
    }
}
int KMP()
{
    int n = strlen(t), m = strlen(s);
    get_next();
    int j = 0, cnt = 0;
    for(int i=0;i<n;i++)
    {
        while(j && s[j] != t[i]) j = next[j];
        if(s[j] == t[i]) j++;
        if(j == m) cnt++;
    }
    return cnt;
}
int main()
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        scanf("%s%s", &s, &t);
        int ans = KMP();
        printf("%d\n", ans);
    }
    return 0;
}