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| #include <iostream>
#include <list>
#define INF 2000000000;
using namespace std;
struct node {
pair<int, int> r;
pair<int, int> b;
int d;
};
int map[10][10], n, m, os[4][2] = { {-1,0}, {0,1}, {1, 0}, {0,-1} };
pair<int, int> h, r, b;
bool visit[10][10][10][10];
list<node> l;
int bfs();
int min(int a, int b) {
return a < b ? a : b;
}
int main() {
cin >> n >> m;
for (int i = 0; i < n; i++) {
string a;
cin >> a;
for (int j = 0; j < m; j++) {
map[i][j] = a[j];
switch (map[i][j]) {
case 'R':
r = { i,j };
break;
case 'B':
b = { i,j };
break;
case 'O':
h = { i,j };
}
}
}
cout << bfs();
}
int bfs() {
visit[r.first][r.second][b.first][b.second] = true;
l.push_back({ {r.first, r.second}, {b.first, b.second}, 0 });
int ans = INF;
while (!l.empty()) {
node cur = l.front();
l.pop_front();
for (int i = 0; i < 4; i++) {
int rr = cur.r.first, rc = cur.r.second, br = cur.b.first, bc = cur.b.second, nd = cur.d + 1;
bool rf = true;
if (i % 2 == 0 && rc == bc) {
if (i == 0 && rr > br)
rf = false;
else if (i == 2 && rr < br)
rf = false;
}
else if (i % 2 == 1 && rr == br) {
if (i == 1 && bc > rc)
rf = false;
else if (i == 3 && bc < rc)
rf = false;
}
bool rh = false, bh = false;
if (rf) {
while (map[rr + os[i][0]][rc + os[i][1]] != '#') {
rr += os[i][0];
rc += os[i][1];
if (map[rr][rc] == 'O') {
rh = true;
rr = rc = -1;
break;
}
}
while (map[br + os[i][0]][bc + os[i][1]] != '#' && (br + os[i][0] != rr|| bc + os[i][1] != rc)) {
br += os[i][0];
bc += os[i][1];
if (map[br][bc] == 'O') {
bh = true;
break;
}
}
}
else {
while (map[br + os[i][0]][bc + os[i][1]] != '#') {
br += os[i][0];
bc += os[i][1];
if (map[br][bc] == 'O') {
bh = true;
br = bc = -1;
break;
}
}
while (map[rr + os[i][0]][rc + os[i][1]] != '#' && (rr + os[i][0] != br || rc + os[i][1] != bc)) {
rr += os[i][0];
rc += os[i][1];
if (map[rr][rc] == 'O') {
rh = true;
break;
}
}
}
if (rh && !bh)
ans = min(ans, nd);
else if (!rh && !bh && !visit[rr][rc][br][bc]) {
visit[rr][rc][br][bc] = true;
l.push_back({ {rr, rc}, {br, bc}, nd });
}
}
}
return ans == 2000000000 ? -1 : ans;
}
|
