Create 3341. Find Minimum Time to Reach Last Room I.cpp

Author: Amber-Mishra-2003

3341. Find Minimum Time to Reach Last Room I.cpp

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+#include <bits/stdc++.h>
+using namespace std;
+using ll = long long;
+struct Node {
+    int r, c;
+    ll t;
+};
+struct Cmp {
+    bool operator()(const Node &a, const Node &b) const {
+        return a.t > b.t;
+    }
+};
+ll minTimeToReach(vector<vector<ll>>& moveTime) {
+    int n = moveTime.size();
+    int m = moveTime[0].size();
+    const ll INF = LLONG_MAX / 4;
+    vector<vector<ll>> dist(n, vector<ll>(m, INF));
+    priority_queue<Node, vector<Node>, Cmp> pq;
+    dist[0][0] = 0;
+    pq.push({0, 0, 0});
+    int dr[4] = {1, -1, 0, 0};
+    int dc[4] = {0, 0, 1, -1};
+    while (!pq.empty()) {
+        Node cur = pq.top();
+        pq.pop();
+        if (cur.t > dist[cur.r][cur.c]) continue;
+        if (cur.r == n - 1 && cur.c == m - 1) return cur.t;
+        for (int i = 0; i < 4; i++) {
+            int nr = cur.r + dr[i];
+            int nc = cur.c + dc[i];
+            if (nr < 0 || nr >= n || nc < 0 || nc >= m) continue;
+            ll arrival = max(moveTime[nr][nc], cur.t) + 1;
+            if (arrival < dist[nr][nc]) {
+                dist[nr][nc] = arrival;
+                pq.push({nr, nc, arrival});
+            }
+        }
+    }
+    return dist[n - 1][m - 1];
+}
+int main() {
+    int n, m;
+    cin >> n >> m;
+    vector<vector<ll>> moveTime(n, vector<ll>(m));
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < m; j++) {
+            cin >> moveTime[i][j];
+        }
+    }
+    ll res = minTimeToReach(moveTime);
+    cout << res << "\n";
+    return 0;
+}