[Topcoder] SRM233

DivI lev2

 

#include <iostream>#include <list>#include <vector>#include <cstring>#include <queue>#include <iterator>#include <algorithm>#include <sstream>using namespace std;#define NODE_NUM(26 * 26 * 26 * 26)typedef struct node {long distance;} node;class SmartWordToy {private:node * vertex;short * visited;vector<string> pattern;public:long str2id(string str) {long sum = 0;for (int i= 0; i < 4; i++) {sum = sum * 26 + str[i] - 'a'; }return sum;}string id2str(long id) {string str(4, 'a');for (int i = 3; i >= 0; i--) {str[i] = ('a' + id % 26);id /= 26;}return str;}public:SmartWordToy() {vertex = new node[NODE_NUM];memset(vertex, -1, sizeof(node) * NODE_NUM);visited = new short[NODE_NUM];memset(visited, 0, sizeof(short) * NODE_NUM);}~SmartWordToy() {delete [] vertex;}int minPresses(string start, string finish, vector<string> forbid) {// construct patternfor (int i = 0; i < forbid.size(); i++) {istringstream iss(forbid[i]);string sub;while (iss >> sub) {pattern.push_back(sub);}}// find the shortest pathqueue<long>q;long start_id = str2id(start);vertex[start_id].distance = 0;visited[start_id] = 1;q.push(start_id);while (!q.empty()) {long cur_id = q.front();q.pop();string cur_str= id2str(cur_id);if (cur_str == finish)return vertex[cur_id].distance;for (int i = 0; i < 4; i++) for (int j = -1; j <= 1; j += 2) {string tmp_str = cur_str;tmp_str[i] += j;tmp_str[i] = (tmp_str[i] - 'a' + 26) % 26 + 'a';long next_id = str2id(tmp_str);if (visited[next_id] == 1) continue;short forbid_flg = 0;for (int k = 0; k < forbid.size(); k++) {int match = 0;for (int l = 0; l < 4; l++) {size_t found = pattern[k * 4 + l].find(tmp_str[l]);if (found != string::npos)match++;else break;}if (match == 4) {forbid_flg = 1;break;}}if (forbid_flg == 0) {vertex[next_id].distance = vertex[cur_id].distance + 1;visited[next_id] = 1;q.push(next_id);}}}return -1;}};int main(){SmartWordToy swt;//cout << swt.str2id("abcd") << endl;//cout << swt.id2str(731) << endl;string start("aaaa");string finish("zzzz");vector<string> forbid;forbid.push_back("bz a a a");forbid.push_back("a bz a a");forbid.push_back("a a bz a");forbid.push_back("a a a bz");cout << swt.minPresses(start, finish, forbid) << endl;return 0;}