POJ 3984

Description

int maze[5][5] = {

	0, 1, 0, 0, 0,

	0, 1, 0, 1, 0,

	0, 0, 0, 0, 0,

	0, 1, 1, 1, 0,

	0, 0, 0, 1, 0,

};

Input

Output

Sample Input

0 1 0 0 0
0 1 0 1 0
0 0 0 0 0
0 1 1 1 0
0 0 0 1 0

Sample Output

(0, 0)
(1, 0)
(2, 0)
(2, 1)
(2, 2)
(2, 3)
(2, 4)
(3, 4)
(4, 4)
#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
#include <algorithm>
using namespace std;

typedef pair<int, int> P;
const int INF = 10000000;
int s[5][5], d[5][5];
int dx[4] = {-1, 1, 0, 0}, dy[4] = {0, 0, -1, 1};
struct node
{
    int x, y;
};
node e, pre[5][5];

void bfs()
{
    queue <P> que;
    fill(d[0], d[0] + 25, INF);

    que.push(P(0, 0));
    d[0][0] = 0;

    while(! que.empty())
    {
        P p = que.front(); que.pop();
        if(p.first == 4 && p.second == 4) break;

        for(int i = 0; i < 4; i++)
        {
            int x = p.first + dx[i], y = p.second + dy[i];
            if(x >= 0 && x < 5 && y >= 0 && y < 5 && s[x][y] == 0 && d[x][y] == INF)
            {
                que.push(P(x, y));
                d[x][y] = d[p.first][p.second] + 1;
                e.x = p.first, e.y = p.second;
                pre[x][y] = e;
            }
        }
    }

    vector <node> path;
    e.x = 4, e.y = 4;
    path.push_back(e);
    for(int i = 4, j = 4; i || j; i = e.x, j = e.y)
    {
        e = pre[i][j];
        path.push_back(e);
    }

    reverse(path.begin(), path.end());
    for(vector <node> :: iterator pp = path.begin(); pp != path.end(); pp++)
        printf("(%d, %d)\n", pp -> x, pp -> y);

}

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

    bfs();

    return 0;
}