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@surinoel
Created August 6, 2019 08:35
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#include <queue>
#include <tuple>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int mat[1000][1000];
int dist[1000][1000][2];
int dx[4] = { 1, -1, 0, 0 };
int dy[4] = { 0, 0, 1, -1 };
int main(void) {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
int sx, sy, ex, ey;
cin >> sx >> sy >> ex >> ey;
sx -= 1;
sy -= 1;
ex -= 1;
ey -= 1;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
cin >> mat[i][j];
}
}
memset(dist, -1, sizeof(dist));
queue<tuple<int, int, int>> q;
q.push(make_tuple(sx, sy, 0));
dist[sx][sy][0] = 0;
while (!q.empty()) {
int x, y, z;
tie(x, y, z) = q.front();
q.pop();
for (int k = 0; k < 4; k++) {
int tx = x + dx[k];
int ty = y + dy[k];
if (tx < 0 || ty < 0 || tx > n - 1 || ty > m - 1) continue;
if (mat[tx][ty] == 0 && dist[tx][ty][z] == -1) {
dist[tx][ty][z] = dist[x][y][z] + 1;
q.push(make_tuple(tx, ty, z));
}
else if (mat[tx][ty] == 1 && z == 0) {
dist[tx][ty][z + 1] = dist[x][y][z] + 1;
q.push(make_tuple(tx, ty, z + 1));
}
}
}
if (dist[ex][ey][0] == -1 && dist[ex][ey][1] == -1) {
cout << "-1\n";
return 0;
}
if (dist[ex][ey][0] == -1) {
cout << dist[ex][ey][1] << '\n';
}
else if (dist[ex][ey][1] == -1) {
cout << dist[ex][ey][0] << '\n';
}
else {
cout << min(dist[ex][ey][0], dist[ex][ey][1]) << '\n';
}
return 0;
}
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