【HDOJ】1857 Word Puzzle

trie树。以puzzle做trie树内存不够，从puzzle中直接找串应该会TLE。其实可以将查询组成trie树，离线做。
扫描puzzle时注意仅三个方向即可。

/* 1857 */
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <deque>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <climits>
#include <cctype>
#include <cassert>
#include <functional>
#include <iterator>
#include <iomanip>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,1024000")

#define sti                set<int>
#define stpii            set<pair<int, int> >
#define mpii            map<int,int>
#define vi                vector<int>
#define pii                pair<int,int>
#define vpii            vector<pair<int,int> >
#define rep(i, a, n)     for (int i=a;i<n;++i)
#define per(i, a, n)     for (int i=n-1;i>=a;--i)
#define clr                clear
#define pb                 push_back
#define mp                 make_pair
#define fir                first
#define sec                second
#define all(x)             (x).begin(),(x).end()
#define SZ(x)             ((int)(x).size())
#define lson            l, mid, rt<<1
#define rson            mid+1, r, rt<<1|1

const int maxr = 505;
const int maxc = 505;
const int maxn = 2e5+5;
const int maxm = 1e4+5;
char s[maxr][maxc], ss[maxc];
int X[maxn], Y[maxn];
int nxt[maxn][26];
int P[maxm];
int l = 1;
int wn = 0;
int n, m;

void init() {
    memset(X, -1, sizeof(X));
    memset(Y, -1, sizeof(Y));
}

inline int newNode() {
    return l++;
}

void Insert(char *s) {
    int i = 0, id;
    int p = 0, q;
    
    while (s[i]) {
        id = s[i] - 'A';
        q = nxt[p][id];
        if (!q)
            q = nxt[p][id] = newNode();
        p = q;
        ++i;
    }
    P[wn++] = p;
}

void Find(char *s, int x, int y) {
    int i = 0, id;
    int p = 0;
    
    while (s[i]) {
        id = s[i] - 'A';
        p = nxt[p][id];
        if (!p)
            return ;
        if (X[p]<0 || x<X[p] || (x==X[p] && y<Y[p])) {
            X[p] = x;
            Y[p] = y;
        }
        ++i;
    }
}

void solve() {
    // horizontal
    rep(i, 0, n) {
        strcpy(ss, s[i]);
        rep(j, 0, m)
            Find(ss+j, i, j);
    }
    
    
    // vertical
    rep(j, 0, m) {
        rep(i, 0, n)
            ss[i] = s[i][j];
        ss[n] = '';
        rep(i, 0, n)
            Find(ss+i, i, j);
    }
    
    
    // diagonal
    int x, y, l;
    
    rep(i, 0, n) {
        x = i;
        y = 0;
        l = 0;
        while (x<n && y<m) {
            ss[l++] = s[x][y];
            ++x;
            ++y;
        }
        ss[l] = '';
        rep(k, 0, l)
            Find(ss+k, i+k, k);
    }
    
    rep(j, 1, m) {
        x = 0;
        y = j;
        l = 0;
        while (x<n && y<m) {
            ss[l++] = s[x][y];
            ++x;
            ++y;
        }
        ss[l] = '';
        rep(k, 0, l)
            Find(ss+k, k, j+k);
    }
    
}

int main() {
    ios::sync_with_stdio(false);
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
        freopen("data.out", "w", stdout);
    #endif
    
    init();
    scanf("%d %d", &n, &m);
    rep(i, 0, n)
        scanf("%s", s[i]);
    getchar();
    getchar();
    while (scanf("%s", ss)!=EOF && ss[0]!='-') {
        Insert(ss);
    }
    
    solve();
    
    int p;
    rep(i, 0, wn) {
        p = P[i];
        printf("%d %d
", X[p], Y[p]);
    }
    
    #ifndef ONLINE_JUDGE
        printf("time = %d.
", (int)clock());
    #endif
    
    return 0;
}