Remember the Word
Since Jiejie can’t remember numbers clearly, he just uses sticks to help himself. Allowing for Jiejie’s
only 20071027 sticks, he can only record the remainders of the numbers divided by total amount ofsticks.The problem is as follows: a word needs to be divided into small pieces in such a way that eachpiece is from some given set of words. Given a word and the set of words, Jiejie should calculate thenumber of ways the given word can be divided, using the words in the set.InputThe input file contains multiple test cases. For each test case: the first line contains the given wordwhose length is no more than 300 000.The second line contains an integer S, 1 ≤ S ≤ 4000.Each of the following S lines contains one word from the set. Each word will be at most 100characters long. There will be no two identical words and all letters in the words will be lowercase.There is a blank line between consecutive test cases.You should proceed to the end of file.OutputFor each test case, output the number, as described above, from the task description modulo 20071027.Sample Inputabcd4abcdabSample OutputCase 1: 2
题意:
给出一个由S个不同单词组成的字典和一个长字符串。吧这个字符串分解成若干个单词的连接,有多少种方法。
题解:
大白
#include#include #include #include #include #include using namespace std;typedef long long ll;int mod = 20071027;const int N = 300005;const int maxnode = 400005;struct Trie { int ch[maxnode][26],val[maxnode]; int siz; void trie_clear() {siz = 1, memset(ch[0],0,sizeof(ch[0]));} int idx (char c) { return c - 'a';} // 插入字符串s,附加信息为v。注意v必须非0,因为0代表“本结点不是单词结点” void trie_insert(const char *s,int v) { int u = 0, n = strlen(s); for(int i = 0; i < n; i++) { int c= idx(s[i]); if(!ch[u][c]) { // 结点不存在 memset(ch[siz],0,sizeof(ch[siz])); val[siz] = 0; // 中间结点的附加信息为0 ch[u][c] = siz++; // 新建结点 } u = ch[u][c];// 往下走 } val[u] = v;// 字符串的最后一个字符的附加信息为v } void trie_find(const char *s, int len, vector & ans) { int u = 0; for(int i = 0; i < len; i++) { if(s[i] == '\0')break; int c= idx(s[i]); if(!ch[u][c]) break; u = ch[u][c]; if(val[u] != 0) ans.push_back(val[u]); } }};Trie P;char s[N], ss[N];int d[N],len[N],n;int solve() { P.trie_clear(); for(int i = 1; i <= n; i++) { scanf("%s", ss); len[i] = strlen(ss); P.trie_insert(ss,i); } memset(d,0,sizeof(d)); int L = strlen(s); d[L] = 1; for(int i = L-1; i >= 0; i--) { vector ans; P.trie_find(s+i,L-i,ans); for(int j = 0; j < ans.size(); j++) { d[i] = (d[i] + d[i+len[ans[j]]]) % mod; } } return d[0];}int main() { int T = 1; while(scanf("%s%d", s,&n)!=EOF) { printf("Case %d: %d\n",T++,solve()); } return 0;}