KMP字符串匹配
我是真的不理解
#include<iostream>
#include<cstdio>
using namespace std;
const int MAXM=10000;
const int MAXN=1000000;
int nextTable[MAXN];
int pattern[MAXN];
int text[MAXN];
void GetNextTable(int m){
int j=0;
nextTable[j]=-1;
int i=nextTable[j];
while(j<m){
if(i==-1||pattern[j]==pattern[i]){
i++;
j++;
nextTable[j]=i;
}else{
i=nextTable[i];
}
}
return;
}
int KMP(int n,int m){
GetNextTable(m);
int i=0;
int j=0;
while(i<n&&j<m){
if(j==-1||text[i]==pattern[j]){
i++;
j++;
}else{
j=nextTable[j];
}
}
if(j==m){
return i-j+1;
}else{
return -1;
}
}
int main()
{
int caseNumber;
scanf("%d",&caseNumber);
while(caseNumber--){
int n,m;
scanf("%d%d",&n,&m);
for(int i=0;i<n;i++){
scanf("%d",&text[i]);
}
for(int j=0;j<m;j++){
scanf("%d",&pattern[j]);
}
printf("%d\n",KMP(n,m));
}
return 0;
}