POJ - 3984 bfs [kuangbin带你飞]专题一

bfs搜索过程中将路径保存下即可。

AC代码

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
const int maxn = 10;

int G[maxn][maxn], d[maxn][maxn], pre[40];
const int dx[] = {1,-1,0,0};
const int dy[] = {0,0,-1,1};

void print(int x, int y){
	int pos = pre[x * 5 + y];

	if(pos != -1) print(pos / 5, pos % 5);
	printf("(%d, %d)\n", x, y);
}

void bfs(){
	memset(d, -1, sizeof(d));
	pre[0] = -1;
	queue<int>q;
	q.push(0);
	d[0][0] = 0;
	while(!q.empty()) {
		int pos = q.front();
		q.pop();
		int x = pos / 5, y = pos % 5;
		if(x == 4 && y == 4) {
			print(x, y);
			return;
		}
		for(int i = 0; i < 4; ++i){
			int px = x + dx[i], py = y + dy[i];
			if(px < 0 || py < 0 || px >= 5 || py >= 5) continue;
			if(G[px][py] || d[px][py] != -1) continue;
			d[px][py] = d[x][y] + 1;
			pre[px * 5 + py] = x * 5 + y;
			q.push(px * 5 + py);
		}
	}
}

int main(){
	for(int i = 0; i < 5; ++i)
	for(int j = 0; j < 5; ++j){
		scanf("%d", &G[i][j]);
	}
	bfs();
	return 0;
}

如有不当之处欢迎指出！