蓝桥杯九宫重排（bfs+用set去重）

题目连接

#define _CRT_SECURE_NO_WARNINGS
#include<cstdio>
#include<iostream>
#include<queue> 
#include<cmath>
#include<set>
#include<cstring>
using namespace std;
char s[4][4], e[4][4];
char  a[10];
struct point {
	int x, y;
	char status[4][4];
	int cnt = 0;
	point() {
	};
	point(int x, int y, char s[4][4] , int cnt) {
		this->x = x; this->y = y;
		for (int i = 0; i<3; i++)
			for (int j = 0; j<3; j++) {
			this->status[i][j] = s[i][j];
		}
		this->cnt = cnt;
	}
}p;
int ll;
int dx[4] = { 0,1,0,-1 };
int dy[4] = { -1,0,1,0 };
bool is_ok(int x, int y) {
	if (x<0 || x>2 || y<0 || y>2)return false;
	return true;
}
bool check(char(*s)[4], char(*e)[4]) {
	for (int i = 0; i<3; i++)
		for (int j = 0; j<3; j++) {
			if (s[i][j] != e[i][j])return false;
		}
	return true;
}
queue<point>que;
set<int>vis;
bool  change(char (*s)[4]) {
	
	int ans = 0;
	for (int i = 0; i < 3; i++)
	for(int j=0;j<3;j++){
		if (s[i][j] == '.')ans = ans * 10;
		else ans = ans * 10 + s[i][j] - '0';
	}
	if (vis.count(ans)) //容器中有相同 
	{
		return 0;
	}
	vis.insert(ans);//插入容器 
	return 1;
}
void bfs() {
	char temp[4][4];
	while (!que.empty()) {
		p = que.front();
		que.pop();
		if (check(p.status,e)) {
			cout << p.cnt << endl;
			return;
		}
		for (int i = 0; i<4; i++) {
			int x = p.x + dx[i];
			int y = p.y + dy[i];
			if (is_ok(x, y)) {
				memcpy(temp, p.status,sizeof(temp));
				temp[p.x][p.y] = temp[x][y];
				temp[x][y] = '.';
				if (change(temp)) {
					que.push(point(x, y, temp, p.cnt + 1));
				}
				
			}
		}
	}
}
int main() {
	scanf("%s", a);
	int c = 0;
	int dxx, dyy;
	for (int i = 0; i<3; i++)
		for (int j = 0; j<3; j++) {
			if (a[c] == '.') {
				dxx = i, dyy= j;
			}
			s[i][j] = a[c++];
		}
	que.push(point(dxx, dyy, s, 0));
	change(s);
	c = 0;
	scanf("%s", a);
	for (int i = 0; i<3; i++)
		for (int j = 0; j<3; j++) {
			e[i][j] = a[c++];
		}
	bfs();
	return 0;
}