POJ 2697 A Board Game （bfs模拟）

比较水的一道题，在4*4的棋盘上有黑白子，现在有某种移动方式，问能否通过它将棋盘从某个状态移动到另一种状态

只要想好怎么保存hash表来去重，其他就差不多了...

#include <iostream>#include <algorithm>#include <cmath>#include<functional>#include <cstdio>#include <cstdlib>#include <cstring>#include <string>#include <vector>#include <set>#include <map>#include <queue>#include <stack>#include <climits>//形如INT_MAX一类的#define MAX 100005#define INF 0x7FFFFFFF#define REP(i,s,t) for(int i=(s);i<=(t);++i)#define ll long long#define mem(a,b) memset(a,b,sizeof(a))#define mp(a,b) make_pair(a,b)#define L(x) x<<1#define R(x) x<<1|1# define eps 1e-5//#pragma comment(linker, "/STACK:36777216") ///传说中的外挂//#pragma comment(linker,"/STACK:102400000,102400000")using namespace std;struct node {    string s;    int step;} a,st,end;map <string, int > vis;queue <node> q;struct MAP {    string s;} pos[1111];int cnt;char tmp[5];string mp[4];void init() {    st.s = "";    end.s = "";    vis.clear();    while(! q.empty()) q.pop();}void move(int posx,int posy, int x,int y, char c) {    string s = "";    for(int i=0; i<4; i++) {        for(int j=0; j<4; j++) {            if(i == posx && j == posy) {                s += c;            } else if(i == x && j == y) {                s += '*';            } else s += mp[i][j];        }    }    pos[cnt++].s = s;}void trans(int x,int y,char c) {    int posx = x;    int posy = y;    for(int i=x; i>=0; i--) {        posx = i;        if(i - 1 < 0 || mp[i-1][y] == 'b' || mp[i-1][y] == 'w') break;    }    move(posx,posy,x,y,c);    posx = x;    posy = y;    for(int i=x; i<4; i++) {        posx = i;        if(i + 1 >= 4 || mp[i+1][y] == 'b' || mp[i+1][y] == 'w') break;    }    move(posx,posy,x,y,c);    posx = x;    posy = y;    for(int i=y; i<4; i++) {        posy = i;        if(i + 1 >= 4 || mp[x][i+1] == 'b' || mp[x][i+1] == 'w') break;    }    move(posx,posy,x,y,c);    posx = x;    posy = y;    for(int i=y; i>=0; i--) {        posy = i;        if(i - 1 < 0 || mp[x][i-1] == 'b' || mp[x][i-1] == 'w') break;    }    move(posx,posy,x,y,c);}void solve() {    cnt = 0;    for(int i=0; i<4; i++) {        for(int j=0; j<4; j++) {            if(mp[i][j] == 'b' || mp[i][j] == 'w') {                trans(i,j,mp[i][j]);            }        }    }}int bfs() {    vis[st.s] = 1;    st.step = 0;    q.push(st) ;    while(! q.empty()) {        node t = q.front();        q.pop();        //cout << t.s << ' ' << t.step << endl;        if(t.s == end.s) {            return t.step;        }        for(int i=0; i<4; i++) mp[i].clear();        for(int i=0; i<4; i++) {            for(int j=0; j<4; j++) {                mp[i] += t.s[i * 4 + j];            }        }        solve();        node tt;        for(int i=0; i<cnt; i++) {            if(vis[pos[i].s] == 1) continue;            vis[pos[i].s] = 1;            tt.s = pos[i].s;            tt.step = t.step + 1;            q.push(tt);        }    }    return -1;}int main() {    int T;    cin >> T;    while(T--) {        init();        for(int i=0; i<4; i++) {            scanf("%s",tmp);            st.s += tmp;        }        for(int i=0; i<4; i++) {            scanf("%s",tmp);            end.s += tmp;        }        printf("%d\n",bfs());    }    return 0;}