poj2001

Trie树，每个结点记录其下面分支的单词总数。

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

struct Node
{
    Node *next[26];
    int count;
} trie[100000];

int ncount;

void ins(Node *proot, char *st)
{
    proot->count++;
    if (st[0] == '\0')
        return;
    if (!proot->next[st[0] - 'a'])
    {
        ncount++;
        proot->next[st[0] - 'a'] = trie + ncount;
    }
    ins(proot->next[st[0] - 'a'], st + 1);
}

void query(Node *proot, char *st)
{
    if (st[0] == '\0')
        return;
    printf("%c", st[0]);
    if (proot->next[st[0] - 'a']->count > 1)
        query(proot->next[st[0] - 'a'], st + 1);
}

int main()
{
    //freopen("t.txt", "r", stdin);
    ncount = 0;
    char st[1005][30];
    memset(trie, 0, sizeof(trie));
    int i = 0;
    while (scanf("%s", st[i]) != EOF && strlen(st[i]) != 0)
    {
        ins(trie, st[i]);
        i++;
    }
    int n = i;
    for (i = 0; i < n; i++)
    {
        printf("%s ", st[i]);
        query(trie, st[i]);
        printf("\n");
    }
    return 0;
}