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;
}