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！