2016夏季练习——KMP

来源：POJ3461

KMP一水，学了好几天

代码：

#include <iostream>#include <cstdio>#include <string>#include <cstring>#include <algorithm>#include <cmath>using namespace std;const int MAXN = 10010;int nxt[MAXN];char m[MAXN];char p[MAXN*100];int lenm,lenp;void get_next(){    int i=0,j;    memset(nxt,0,sizeof(nxt));    nxt[0]=j=-1;    while(i<lenm){        if(j==-1||m[i]==m[j]){            i++;j++;            if(m[i]!=m[j]){                nxt[i] = j;            }            else                nxt[i] = nxt[j];        }        else            j = nxt[j];    }}int ans=0;void kmp(){    int i,j;    i=j=0;    while(i<lenp){        if(j==-1||m[j] == p[i]){            i++;            j++;        }        else            j=nxt[j];        if(j==lenm){            ans++;            j = nxt[j];        }    }}int main(){int T;scanf("%d",&T);getchar();while(T--){        gets(m);        gets(p);        lenm = strlen(m);        lenp = strlen(p);        //cout<<m<<endl<<p<<endl;        get_next();        ans = 0;        kmp();        cout<<ans<<endl;}return 0;}