POJ2752_通过kmpNext数组的性质求一个字符串的公共同前后缀

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const int maxn = 500000;
char S[maxn];
int Next[maxn];
int V[maxn];
int Vcnt;
void getNext(int len)
{
len++;//用于把\0也给统计进去
int k = -1;
Next[0] = -1;
for (int i = 0; i < len;)
{
while (k > -1 && S[i] != S[k])
{
k = Next[k];
}
i++;
k++;
Next[i] = k;//使用没有优化的方法构建next数组
}
}

void solve(int len)
{
len++;
for (int i = len - 1; i >= 0; )
{
V[Vcnt++] = Next[i];
i = Next[i];
}
}
int main()
{
while (~scanf("%s", S))
{
int len = strlen(S);
Vcnt = 0;
getNext(len);
V[Vcnt++] = len;
solve(len);
bool flag = true;
for (int i = Vcnt - 1; i >= 0; i--)
{
if (!flag)
{
cout << " ";
}
if (V[i] > 0)
{
cout << V[i];
flag = false;
}

}
cout << endl;
}

}