HDU 1298 T9 ( 字典树 )

#include<string.h>
#include<stdio.h>
#include<malloc.h>
#include<iostream>
#include<algorithm>
#include<map>
using namespace std;
const int maxn = 27;
int tot = 0, n, m;
const int INF = 0x3f3f3f3f;
char mp[][5]{ ///模拟数字键盘，因为是从2开始，所以0和1都赋值上一个‘@‘代表空
    {‘@‘,‘@‘,‘@‘,‘@‘,‘@‘},
    {‘@‘,‘@‘,‘@‘,‘@‘,‘@‘},
    {‘a‘,‘b‘,‘c‘,‘@‘,‘@‘},
    {‘d‘,‘e‘,‘f‘,‘@‘,‘@‘},
    {‘g‘,‘h‘,‘i‘,‘@‘,‘@‘},
    {‘j‘,‘k‘,‘l‘,‘@‘,‘@‘},
    {‘m‘,‘n‘,‘o‘,‘@‘,‘@‘},
    {‘p‘,‘q‘,‘r‘,‘s‘,‘@‘},
    {‘t‘,‘u‘,‘v‘,‘@‘,‘@‘},
    {‘w‘,‘x‘,‘y‘,‘z‘,‘@‘}
};

struct Trie
{
    Trie *Next[maxn];
    int v;
    inline void init(const int val){
        this->v = val;
        for(int i=0; i<maxn; i++)
            this->Next[i] = NULL;
    }
};
Trie *root;

void CreateTrie(char *str, int val)
{
    int len = strlen(str);
    Trie *p = root, *tmp;
    for(int i=0; i<len; i++){
        int idx = str[i]-‘a‘;

        if(p->Next[idx] == NULL){
            tmp = (Trie *)malloc(sizeof(Trie));
            tmp->init(val);
            p->Next[idx] = tmp;
        }else (p->Next[idx]->v) += val;///赋上频率权值

        p = p->Next[idx];
    }
}

inline void DelTrie(Trie *T)
{
    if(T == NULL) return ;
    for(int i=0; i<maxn; i++){
        if(T->Next[i] != NULL)
            DelTrie(T->Next[i]);
    }
    free(T);
    return ;
}

char str[111], ans[111], now[111];
int tmp, MaxVal;

void DFS(int pos, int len, Trie *NOD)
{
    if(pos == len){///递归出口，看看频率是否更优，更新答案
        if(NOD->v > MaxVal){
            strcpy(ans, now);
            MaxVal = NOD->v;
        }
        return ;
    }
    int idx = str[pos]-‘0‘;

    for(int i=0; mp[idx][i]!=‘@‘; i++){///枚举这个数字建的所有字母，遇到‘@‘结束
        int id = mp[idx][i] - ‘a‘;
        if(NOD->Next[id]){ ///如果字典树关于这个字母的节点不为空的话，则进一步搜索
            now[pos] = mp[idx][i];///now是保存一下暂时现在构造出来的字符串，以便更新
            now[pos+1] = ‘\0‘;
            DFS(pos+1, len, NOD->Next[id]);///进一步搜索
        }
    }
}

int main(void)
{
    int nCase;
    scanf("%d", &nCase);
    
    for(int Case=1; Case<=nCase; Case++){
        root = (Trie *)malloc(sizeof(Trie));
        root->init(0);
        scanf("%d", &n);
        int tmpVal;
        for(int i=0; i<n; i++){
            scanf("%s %d", str, &tmpVal);
            CreateTrie(str, tmpVal);
        }
        printf("Scenario #%d:\n", Case);
        scanf("%d", &m);

        for(int i=0; i<m; i++){
            scanf("%s", str);
            int len = strlen(str);

            for(int j=1; j<len; j++){///枚举长度
                MaxVal = -INF;
                DFS(0, j, root);
                if(MaxVal == -INF) puts("MANUALLY");
                else puts(ans);
            }
            puts("");
        }puts("");
        DelTrie(root);
    }
    return 0;
}