poj2752

poj2752
找所有的前缀等于后缀，那就是找所有前缀等于后缀的前缀，递归再用栈存一下

#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
#include<cmath>
#include<ctime>
#include<set>
#include<map>
#include<stack>
#include<cstring>
#define inf 2147483647
#define ls rt<<1
#define rs rt<<1|1
#define lson ls,nl,mid,l,r
#define rson rs,mid+1,nr,l,r
#define N 400010
#define For(i,a,b) for(int i=a;i<=b;i++)
#define p(a) putchar(a)
#define g() getchar()

using namespace std;
int kmp[N];
int lb,k;
char b[N];
stack<int>s;
void in(int &x){
    int y=1;
    char c=g();x=0;
    while(c<'0'||c>'9'){
        if(c=='-')y=-1;
        c=g();
    }
    while(c<='9'&&c>='0'){
        x=(x<<1)+(x<<3)+c-'0';c=g();
    }
    x*=y;
}
void o(int x){
    if(x<0){
        p('-');
        x=-x;
    }
    if(x>9)o(x/10);
    p(x%10+'0');
}

void clear(){
    k=0;
    memset(kmp,0,sizeof(kmp));
}

int main(){
    while(cin>>(b+1)){
        clear();
        lb=strlen(b+1);
        For(i,2,lb){
            while(k&&b[i]!=b[k+1])
                k=kmp[k];
            if(b[k+1]==b[i])
                k++;
            kmp[i]=k;
        }
        k=lb;
        s.push(lb);
        while(kmp[k]>0){
            s.push(kmp[k]);
            k=kmp[k];
        }
        while(!s.empty()){
            o(s.top());p(' ');
            s.pop();
        }
        p('\n');
    }
    return 0;
}