Ultraviolet A 1401-remember the word (trie + dp)

Ultraviolet A 1401-remember the word

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Question: given some words, and a long string, ask this long string to be split into existing words, which can be split into several methods.

Train of Thought: trie, first build the word into trie, and then perform DP, DP [I] to indicate the situation that starts with I, then, for each State, you only need to find the corresponding word starting with I on the trie tree, and then DP [I] = sum {DP [I + Len]} performs state transfer.

Code:

#include <cstdio>#include <cstring>const int MOD = 20071027;const int N = 300005;char str[N], word[105];int S, sz;struct Node {    int next[26], val;} node[N];void insert(char *str) {    int len = strlen(str);    int u = 0;    for (int i = 0; i < len; i++) {int v = str[i] - 'a';if (node[u].next[v])    u = node[u].next[v];else {    node[u].next[v] = sz++;    u = node[u].next[v];    node[u].val = 0;    memset(node[u].next, 0, sizeof(node[u].next));}    }    node[u].val = 1;}void init() {    sz = 1;    memset(node[0].next, 0, sizeof(node[0].next));    node[0].val = 0;}int dp[N];void find(int i) {    int u = 0;    dp[i] = 0;    for (int j = i; str[j]; j++) {int v = str[j] - 'a';if (!node[u].next[v]) return;       u = node[u].next[v];if (node[u].val) dp[i] = (dp[i] + dp[j + 1]) % MOD;    }}int main() {    int cas = 0;    while (~scanf("%s", str)) {scanf("%d", &S);init();while (S--) {    scanf("%s", word);    insert(word);}int len = strlen(str);dp[len] = 1;for (int i = len - 1; i >= 0; i--)    find(i);printf("Case %d: %d\n", ++cas, dp[0]);    }    return 0;}