【字符串最小(大)表示法+KMP求循环节】hdoj 3374 String Problem

首先用 字符串最小(大)表示法 解决第一个问题

然后用 KMP求循环节 解决第二个问题

 

#include <cstdio> #include <cstring> #define NUM 1000005 void getnext(char str[],int next[]) { next[0] = -1; int i=0; int j=-1; int len = strlen(str); while (i<len) { if (j==-1||str[i]==str[j]) { i++; j++; next[i] = j; } else { j=next[j]; } } } int MinAndMaxRepresentation(char *s, bool bMin = true) { int i = 0, j = 1, k = 0, l = strlen(s), sub; while (i<l && j<l && k<l) { sub = s[(i+k)%l] - s[(j+k)%l]; if (sub == 0) k++; else { if (bMin?sub > 0:sub < 0) i += k+1; else j += k+1; if (i == j) j++; k = 0; } } return i<j?i:j; } char str[NUM]; int next[NUM]; int main() { int len; int minlen; int num; while (scanf("%s", str) != EOF) { len = strlen(str); getnext(str, next); if (len % (len-next[len]) == 0) minlen = len-next[len]; else minlen = len; num = len / minlen; //printf("%d/n", minlen); printf("%d %d %d %d/n", MinAndMaxRepresentation(str)+1, num, MinAndMaxRepresentation(str, false)+1, num); } return 0; } /* String Problem Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 290 Accepted Submission(s): 110 Problem Description Give you a string with length N, you can generate N strings by left shifts. For example let consider the string “SKYLONG”, we can generate seven strings: String Rank SKYLONG 1 KYLONGS 2 YLONGSK 3 LONGSKY 4 ONGSKYL 5 NGSKYLO 6 GSKYLON 7 and lexicographically first of them is GSKYLON, lexicographically last is YLONGSK, both of them appear only once. Your task is easy, calculate the lexicographically fisrt string’s Rank (if there are multiple answers, choose the smallest one), its times, lexicographically last string’s Rank (if there are multiple answers, choose the smallest one), and its times also. Input Each line contains one line the string S with length N (N <= 1000000) formed by lower case letters. Output Output four integers separated by one space, lexicographically fisrt string’s Rank (if there are multiple answers, choose the smallest one), the string’s times in the N generated strings, lexicographically last string’s Rank (if there are multiple answers, choose the smallest one), and its times also. Sample Input abcder aaaaaa ababab Sample Output 1 1 6 1 1 6 1 6 1 3 2 3 */