KMP算法

字符串快速匹配算法

#include<iostream>
#include<cstring>
#include<cmath>
#include<ctime>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
using namespace std;
int i,n,T,l1,l2,j,k;
int next1[11000];
char s1[1100000],s2[11000];
int main()
{
// freopen("a.txt","r",stdin);
cin>>T;
getchar();
while(T --)
{
gets(s1);
gets(s2);
l1 = strlen(s1);
l2 = strlen(s2);
next1[0] = -1;
j = 0;k = -1;
while(j < l2)
{
if(s2[j]==s2[k]||k==-1)next1[++j] = ++k;
else k = next1[k];
}
i = 0;
j = 0;
while(i < l1&&j < l2)
{
if(s1[i]==s2[j]||j==-1) {i++;j++;}
else j = next1[j];
}
if(j==l2) printf("%d\n",i-j+1);
else printf("::>_<::\n");
}
return 0;
}