KMP水题

HUST 1010 The Minimum Length

题目传送： The Minimum Length

AC代码：

#include <map>
#include <set>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <cctype>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define INF 0x7fffffff
using namespace std;

char s[1000005];

int s_next[1000005];

int main() {
    while(scanf("%s", s) != EOF) {
        memset(s_next, 0, sizeof(s_next));
        s_next[0] = -1;
        int i = 0, j = -1;
        int len = strlen(s);
        while(i < len) {
            if(j == -1 || s[i] == s[j]) s_next[++ i] = ++ j;
            else j = s_next[j];
        }

        printf("%d\n", len - s_next[len]);  //即输出最小循环节
    }
    return 0;
}

POJ 2406 Power Strings

题目传送：Power Strings

AC代码：

#include <map>
#include <set>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <cctype>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define INF 0x7fffffff
using namespace std;

char s[1000005];

int s_next[1000005];

int main() {
    while(scanf("%s", s) != EOF) {
        if(strcmp(s, ".") == 0) break;

        memset(s_next, 0, sizeof(s_next));
        s_next[0] = -1;

        int len = strlen(s);
        int i = 0, j = -1;
        while(i < len) {
            if(j == -1 || s[i] == s[j]) s_next[++ i] = ++ j;
            else j = s_next[j];
        }

        if(len % (len - s_next[len]) == 0)  //特判 
            printf("%d\n", len / (len - s_next[len]));  
        else printf("1\n");

    }
    return 0;
}

POJ 2752 Seek the Name, Seek the Fame

题目传送：Seek the Name, Seek the Fame

AC代码：

#include <map>
#include <set>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <cctype>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define INF 0x7fffffff
using namespace std;

char s[400005];

int s_next[400005];

void fun(int len) {
    if(len <= 1) return;
    fun(s_next[len]);
    if(s_next[len] != 0)printf("%d ", s_next[len]);
}

int main() {
    while(scanf("%s", s) != EOF) {
        s_next[0] = -1;
        int len = strlen(s);
        int i = 0, j = -1;
        while(i < len) {
            if(j == -1 || s[i] == s[j]) s_next[++ i] = ++ j;
            else j = s_next[j];
        }

        fun(len);//递归打印 

        printf("%d\n", len);
    }
    return 0;
}

HDU 2594 Simpsons’ Hidden Talents

题目传送：Simpsons’ Hidden Talents

AC代码：

#include <map>
#include <set>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <cctype>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define INF 0x7fffffff
using namespace std;

char s1[100005];
char s2[100005];

int s_next[100005];

int main() {
    while(scanf("%s %s", s1, s2) != EOF) {
        int len1 = strlen(s1);
        int len2 = strlen(s2);
        for(int i = len1, j = 0; j <= len2; i ++, j ++) {
            s1[i] = s2[j];
        }
//      printf("%s\n", s1);

        int len = len1 + len2;
        s_next[0] = -1;
        int i = 0, j = -1;
        int mi = min(len1, len2);
        while(i < len) {
            if((j == -1 || s1[i] == s1[j]) && j < mi) { //最大前缀后缀只能算小于mi的，大于等于mi就不对了，因为是比较两个字符串的前缀和后缀  
                s_next[++ i] = ++ j;
            } 
            else j = s_next[j];
        }

        int t = s_next[len];

        if(t > 0) {

            for(int i = 0; i < t; i ++) {
                printf("%c", s1[i]);
            }
            printf(" %d\n", t);
        }
        else printf("0\n");

    }
    return 0;
}