UVA 1401 Remember the Word (trie + dp)

来源：互联网发布：linux启动停在进度条编辑：程序博客网时间：2024/05/07 07:20

第一次写trie, 看别人的代码看懂的，顺便学了一下dp。

#include <iostream>#include <cstring>#include <cstdio>#include <vector>#define mod 20071027;using namespace std;char str[300010], s[110];int dp[300010];struct Trie{    int ch[400010][26];    int val[400010];    int sz;    void clearr()    {        sz = 1;        memset(ch, 0, sizeof(ch));    }    int idc(char c)    {        return c - 'a';    }    void insertt(char *s, int lenn)    {        int u = 0;        for(int i = 0; i < lenn; i++)        {            int c = idc(s[i]);            if(!ch[u][c])            {                val[sz] = 0;                ch[u][c] = sz++;            }            u = ch[u][c];        }        val[u] = lenn;    }    void find_prefix(char *s, int len, vector<int>& ans)    {        int u = 0;        for(int i = 0; i < len; i++)        {            int c = idc(s[i]);            if(ch[u][c])            {                u = ch[u][c];                if(val[u])                    ans.push_back(val[u]);            }            else                break;        }    }}test;int main(){    int kase = 0;    while(~scanf("%s", str))    {        memset(dp, 0, sizeof(dp));        int len = strlen(str);        test.clearr();        int S;        scanf("%d", &S);        for(int i = 1; i <= S; i++)        {            scanf("%s", s);            int lenn = strlen(s);            test.insertt(s, lenn);        }        dp[len] = 1;        for(int i = len - 1; i >= 0; i--)        {            vector<int> ans;            test.find_prefix(str + i, len - i, ans);            for(int j = 0; j < ans.size(); j++)            {                dp[i] = (dp[i] + dp[i + ans[j]]) % mod;            }        }        printf("Case %d: %d\n", ++kase, dp[0]);    }}

0 0