leetcode 日经贴，python code -Word Search II

来源：互联网发布：java 垃圾评论过滤编辑：程序博客网时间：2024/06/05 15:22
Word Search II
struct TrieNode {    TrieNode (){        memset(next, 0, sizeof(next));        id = -1;        count = 0;    }    TrieNode* next[26];    int id, count;};class Solution {public:    Solution() {        root = new TrieNode();    }        vector<string> findWords(vector<vector<char>>& board, vector<string>& words) {        vector<string> ans;        int R = board.size();        if (!R) {            return ans;        }        int C = board[0].size();        if (!C) {            return ans;        }        sort(words.begin(), words.end());        int wordslen = words.size();        if (!wordslen) {            return ans;        }        for (int i = 0; i < wordslen; ++i) {            //did't insert the same word twice            if (i == 0 || words[i] != words[i - 1]) {                insert(words[i].c_str(), i);            }        }        vector<vector<bool> > visit(R);        for (int i = 0; i < R; ++i) {            visit[i].resize(C);        }        vector<int> matchids;                for (int i = 0; i < R; ++i) {            for (int j = 0; j < C; ++j) {                match(root, board, visit, R, C, i, j, matchids);            }        }        sort(matchids.begin(), matchids.end());        for (int i = 0; i < matchids.size(); ++i) {            ans.push_back(words[matchids[i]]);        }        return ans;    }    private:    TrieNode* root;    const static int dir[4][2];    void insert(const char* s, int id) {        TrieNode* p = root;        p->count++;        while (*s) {            if (!p->next[*s - 'a']) {                p->next[*s - 'a'] = new TrieNode();            }            p = p->next[*s - 'a'];            p->count++;            ++s;        }        p->id = id;    }    int match(TrieNode* cur, vector<vector<char> >& board, vector<vector<bool> >& visit,        int R, int C, int r, int c, vector<int>& matchids) {        if (!cur) {            return 0;        }        int child = board[r][c] - 'a';        if (!cur->next[child]) {            return 0;        }        TrieNode* next = cur->next[child];        int matchcnt = 0;        if (next->id != -1) {            matchids.push_back(next->id);            if (next->count == 1) {                delete next;                cur->next[child] = NULL;                return 1;            } else {                matchcnt++;                next->id = -1;            }        }        visit[r][c] = true;        for (int d = 0; d < 4; ++d) {            int nr = r + dir[d][0];            int nc = c + dir[d][1];            if (nr >= 0 && nr < R && nc >= 0 && nc < C && !visit[nr][nc]) {                matchcnt += match(next, board, visit, R, C, nr, nc, matchids);            }        }        visit[r][c] = false;        if (next->count - matchcnt == 0) {            delete next;            cur->next[child] = NULL;        } else {            next->count -= matchcnt;        }        return matchcnt;    }};const int Solution::dir[4][2] = {1, 0, -1, 0, 0, 1, 0, -1};
0 0