Kattis - String Matching(kmp)

String Matching

Input

Output

p
Popup
helo
Hello there!
peek a boo
you speek a bootiful language
anas
bananananaspaj

2 4

5
7

题意

思路1

思路2

代码1

#include<stdio.h>
#include<string.h>
using namespace std;
int const MAXM = 4000000;
char s[MAXM], t[MAXM];
int next[MAXM], n;
int shuchu[MAXM];
void get_next()
{
next[0] = -1;
int i = 0, j = -1;
while (t[i] != '\0')
{
if (j == -1 || t[i] == t[j])
{
i++;
j++;
next[i] = j;
}
else
j = next[j];
}
}

int KMP()
{
get_next();
int i = 0, j = 0, ans = 0, len = strlen(t);
while (s[i])
{
if (j == -1 || s[i] == t[j])
{
i++;
j++;
}
else
j = next[j];
if (j == len)
{
j = next[j];
shuchu[ans++] = i;
}
}
return ans;
}

int main()
{

while (gets(t)) {
gets(s);
int ss = KMP();
for (int i = 0; i < ss; i++)
{
if (i)printf(" ");
printf("%d", shuchu[i]-strlen(t));
}
puts("");
}
}

代码2

#include<bits/stdc++.h>
using namespace std;
int main(){
string str1,str2;
int cnt[100000];
while(getline(cin,str1)){
getline(cin,str2);
int pos=0,x=0;
while(str2.find(str1,x)!=-1&&x<str2.size()){
cnt[pos++]=str2.find(str1,x);
x=cnt[pos-1]+1;
}
for(int i=0;i<pos;i++){
printf("%d%c",cnt[i],i==pos-1?'\n':' ');
}
}
return 0;
}