poj1077 /hdoj 1043 Eight

这道题用启发式搜索，我在北大网站上可以过，杭电网站上超时，看来杭电的数据有点变态了。

#include <stdio.h>#include <set>#include <queue>#include <string.h>using namespace std;int target_pos[10][2];char buf[100];struct state{int pos_i, pos_j;unsigned char m[4][4];int step;int weight;char solution[100];};priority_queue<struct state> pq;set<unsigned int> hash_table;bool operator < (const struct state &a, const struct state &b){if(a.weight > b.weight)return true;else if(a.weight < b.weight)return false;else{if(a.step > b.step)return true;elsereturn false;}}unsigned int _hash(const struct state &sta){unsigned int sum;int cifang, i, j;cifang = 1;sum = 0;for(i=1; i<=3; i++)for(j=1; j<=3; j++){sum += cifang * sta.m[i][j];cifang *= 10;}return sum;}void init_target_pos(){target_pos[1][0] = 1;target_pos[1][1] = 1;target_pos[2][0] = 1;target_pos[2][1] = 2;target_pos[3][0] = 1;target_pos[3][1] = 3;target_pos[4][0] = 2;target_pos[4][1] = 1;target_pos[5][0] = 2;target_pos[5][1] = 2;target_pos[6][0] = 2;target_pos[6][1] = 3;target_pos[7][0] = 3;target_pos[7][1] = 1;target_pos[8][0] = 3;target_pos[8][1] = 2;target_pos[9][0] = 3;target_pos[9][1] = 3;}int _abs(int x){return x>0 ? x : -1*x;}void get_weight(struct state &sta){int i, j;int sum;sum = 0;for(i=1; i<=3; i++)for(j=1; j<=3; j++){if(sta.m[i][j] <= 8){sum += _abs(i-target_pos[sta.m[i][j]][0]);sum += _abs(j-target_pos[sta.m[i][j]][1]);}}sta.weight = sum+sta.step;}bool find_solution;void print_arr(const struct state &sta){int i, j;for(i=1; i<=3; i++){for(j=1; j<=3; j++)printf("%d ", sta.m[i][j]);printf("\n");}}void bfs(){struct state sta, sta_top;int hv;while(!pq.empty()){memcpy(&sta_top, &(pq.top()), sizeof(struct state));pq.pop();//printf("step=%d weight=%d\n", sta_top.step, sta_top.weight);//print_arr(sta_top);if(_hash(sta_top) == 987654321){sta_top.solution[sta_top.step+1] = '\0';printf("%s\n", sta_top.solution+1);find_solution = true;break;}memcpy(&sta, &sta_top, sizeof(struct state));if(sta.pos_i >= 2){sta.m[sta.pos_i][sta.pos_j] = sta.m[sta.pos_i-1][sta.pos_j];sta.m[sta.pos_i-1][sta.pos_j] = 9;hv = _hash(sta);if(hash_table.find(hv) == hash_table.end()){sta.pos_i--;sta.step++;sta.solution[sta.step] = 'u';get_weight(sta);hash_table.insert(hv);pq.push(sta);}}memcpy(&sta, &sta_top, sizeof(struct state));if(sta.pos_i <= 2){sta.m[sta.pos_i][sta.pos_j] = sta.m[sta.pos_i+1][sta.pos_j];sta.m[sta.pos_i+1][sta.pos_j] = 9;hv = _hash(sta);if(hash_table.find(hv) == hash_table.end()){sta.pos_i++;sta.step++;sta.solution[sta.step] = 'd';get_weight(sta);hash_table.insert(hv);pq.push(sta);}}memcpy(&sta, &sta_top, sizeof(struct state));if(sta.pos_j >= 2){sta.m[sta.pos_i][sta.pos_j] = sta.m[sta.pos_i][sta.pos_j-1];sta.m[sta.pos_i][sta.pos_j-1] = 9;hv = _hash(sta);if(hash_table.find(hv) == hash_table.end()){sta.pos_j--;sta.step++;sta.solution[sta.step] = 'l';get_weight(sta);hash_table.insert(hv);pq.push(sta);}}memcpy(&sta, &sta_top, sizeof(struct state));if(sta.pos_j <= 2){sta.m[sta.pos_i][sta.pos_j] = sta.m[sta.pos_i][sta.pos_j+1];sta.m[sta.pos_i][sta.pos_j+1] = 9;hv = _hash(sta);if(hash_table.find(hv) == hash_table.end()){sta.pos_j++;sta.step++;sta.solution[sta.step] = 'r';get_weight(sta);hash_table.insert(hv);pq.push(sta);}}}}void func(struct state &sta){init_target_pos();hash_table.clear();while(!pq.empty())pq.pop();get_weight(sta);hash_table.insert(_hash(sta));pq.push(sta);find_solution = false;bfs();if(!find_solution)printf("unsolvable\n");}int main(void){int i;int ii, jj;struct state sta;//freopen("input.dat", "r", stdin);while(gets(buf)){if(buf[0] == '\0')break;ii = jj = 1;for(i=0; i<=strlen(buf); i++){if(buf[i]>='1'&&buf[i]<='8'){sta.m[ii][jj] = buf[i]-'0';jj++;if(jj == 4){ii++;jj = 1;}}else if(buf[i] == 'x'){sta.m[ii][jj] = 9;sta.pos_i = ii;sta.pos_j = jj;jj++;if(jj == 4){ii++;jj = 1;}}}sta.step = 0;func(sta);}return 0;}