【POJ】3630 Phone List

静态字典树。

#include <cstdio>
#include <cstring>
#include <cstdlib>

#define MAXN 10005

typedef struct Trie {
    bool v;
    Trie *next[10];
    Trie() {
        v = false;
        for (int i=0; i<10; ++i)
            next[i] = NULL;
    }
} Trie;

Trie tries[MAXN*10];
int num;

bool create(char str[]) {
    int i = 0, id;
    Trie *p = tries;
    bool ret = false;

    while (str[i]) {
        id = str[i] - '0';
        ++i;
        if (p->next[id] == NULL) {
            p->next[id] = &tries[num];
            ++num;
            ret = true;
        } else {
            if (p->next[id]->v == true)
                return false;
        }
        p = p->next[id];
    }
    p->v = true;
    return ret;
}

int main() {
    int case_n, n;
    char buf[12];
    bool f;

    scanf("%d", &case_n);

    while (case_n--) {
        scanf("%d", &n);
        f = true;
        num = 1;
        while (n--) {
            scanf("%s", buf);
            if (f)
                f = create(buf);
        }
        if (f) printf("YES
");
        else   printf("NO
");
        for (int i=0; i<num; ++i) {
            tries[i].v = false;
            memset(tries[i].next, 0, sizeof(tries[i].next));
        }
    }

    return 0;
}