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| #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
int N, K;
const ll MAX_DIST = 2500000000l;
vector<ll> cowBreed;
bool reachable[60][60];
vector<bool> visited;
vector<ll> distanceFromOne;
vector<vector<ll>> cowBreedLists;
ll ans = LONG_MAX;
priority_queue<pll, vector<pll>, greater<pll>> pq;
inline void insert(int v, int n) {
if (!visited[v]) {
ll d = distanceFromOne[n] + abs(v - n);
if (d < distanceFromOne[v]) {
distanceFromOne[v] = d;
pq.push(make_pair(distanceFromOne[v], v));
}
}
}
int main() {
cin >> N >> K;
cowBreed.resize(N + 1);
visited.resize(N + 1, false);
cowBreedLists.resize(K + 1, vector<ll>());
distanceFromOne.resize(N + 1, MAX_DIST);
for (int i = 1; i <= N; i++) {
cin >> cowBreed[i];
cowBreedLists[cowBreed[i]].push_back(i);
}
for (int i = 1; i <= K; i++) {
for (int j = 1; j <= K; j++) {
char c;
cin >> c;
reachable[i][j] = (c == '1');
}
}
pq.push({0, 1});
distanceFromOne[1] = 0;
while (!pq.empty()) {
ll n = pq.top().second;
pq.pop();
if (visited[n]) {
continue;
}
if (n == N) {
ans = min(ans, distanceFromOne[n]);
}
// special handling
if (reachable[cowBreed[n]][cowBreed[N]]) {
ans = min(ans, distanceFromOne[n] + N - n);
}
visited[n] = true;
for (int kk = 1; kk < K + 1; kk++) {
if (reachable[cowBreed[n]][kk]) {
int left = 0;
auto it = upper_bound(cowBreedLists[kk].begin(), cowBreedLists[kk].end(), n);
if (it != cowBreedLists[kk].end()) {
// insert right
insert(*it, n);
}
// insert left
if (kk == cowBreed[n]) {
// special case if same breed, don't push self again
if (it - cowBreedLists[kk].begin() >= 2) {
left = *(it - 2);
}
}
else {
if (it != cowBreedLists[kk].begin()) {
left = *(it - 1);
}
}
if (left != 0) {
insert(left, n);
}
}
}
}
if (ans == LONG_MAX) {
cout << "-1";
}
else {
cout << ans;
}
return 0;
}
|