HDU 1686 - Oulipo(kmp)

Problem link

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分析：

kmp匹配

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代码：

#include <cstdio>#include <cstring>const int maxn = 1000010;char w[maxn], t[maxn];int _next[maxn];void get_next() {    int w_len = strlen(w);    int i = 0, j;    _next[0] = j = -1;    while (i < w_len) {        if (j == -1 || w[j] == w[i]) {            i++;            j++;            _next[i] = j;        } else {            j = _next[j];        }    }}int get_times(){    int ans = 0;    int w_len = strlen(w);    int t_len = strlen(t);    int i = 0, j = 0;    while (j < t_len) {        if (i == -1 || w[i] == t[j]) {            i++;            j++;        } else {            i = _next[i];        }        if (i == w_len) {            ans++;            i = _next[i];        }    }    return ans; }int main() {    int T;    scanf("%d", &T);    while (T--) {        memset(w, 0, sizeof(w));        memset(t, 0, sizeof(t));        memset(_next, 0, sizeof(_next));        scanf("%s %s", w, t);        get_next();        printf("%d\n", get_times());    }    return 0;}