【POJ 2752】 Seek the Name, Seek the Fame

【题目链接】

            点击打开链接

【算法】

         KMP

         沿着失配指针扫一遍即可

【代码】

         

#include <algorithm>
#include <bitset>
#include <cctype>
#include <cerrno>
#include <clocale>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <limits>
#include <list>
#include <map>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <utility>
#include <vector>
#include <cwchar>
#include <cwctype>
#include <stack>
#include <limits.h>
using namespace std;
#define MAXL 400010

int i,len,pos;
char s[MAXL];
int next[MAXL];
vector<int> ans;

template <typename T> inline void read(T &x) {
    int f = 1; x = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) { if (c == '-') f = -f; }
    for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0';
    x *= f;
}

template <typename T> inline void write(T x) {
    if (x < 0) { putchar('-'); x = -x; }
    if (x > 9) write(x/10);
    putchar(x%10+'0');
}

template <typename T> inline void writeln(T x) {
    write(x);
    puts("");
}

inline void getnext() {
        int i,pos;
        next[1] = 0;
        for (i = 2; i <= len; i++) {
                pos = next[i-1];
                while (pos > 0 && s[pos+1] != s[i]) pos = next[pos];
                if (s[pos+1] == s[i]) next[i] = pos + 1;
                else next[i] = 0;
        }    
}

int main() {
        
        while (scanf("%s",s+1) != EOF) {
                len = strlen(s+1);
                getnext();    
                ans.clear();
                pos = len;
                while (pos > 0) {
                        ans.push_back(pos);
                        pos = next[pos];
                }
                reverse(ans.begin(),ans.end());
                write(ans[0]);
                for (i = 1; i < ans.size(); i++) {
                        putchar(' ');
                        write(ans[i]);
                }
                puts("");
        }
        
        return 0;
    
}