update

bailian/4130.saving-tang-monk/main.cc

@@ -1,6 +1,6 @@
 #include <cstdio>
 #include <cstring>
-#include <queue>
+#include <queue>  // Use priority queue to save your time & life.
 
 using namespace std;
 
@@ -8,44 +8,36 @@ const int N = 100;
 const int M = 9;
 const int S = 5;
 
-const char dx[4] = {1, 0, -1, 0};
-const char dy[4] = {0, 1, 0, -1};
+const short dx[4] = {1, 0, -1, 0};
+const short dy[4] = {0, 1, 0, -1};
 
 char map[N][N + 1];
-char snake[N][N];
-bool flag[N][N][M + 1][1 << S];
+short snake[N][N];
+bool flag[N][N][M + 1];
 
 struct Pos {
-  char r;
-  char c;
-  char key;
-  bool kill;
-  char died;
+  short r;
+  short c;
+  short key;
+  short kill;
   int t;
-  Pos(char r = 0, char c = 0, char key = 0, bool kill = false, char died = 0,
-      int t = 0)
-      : r(r), c(c), key(key), kill(kill), died(died), t(t) {}
+  Pos(short r = 0, short c = 0, short key = 0, short kill = 0, int t = 0)
+      : r(r), c(c), key(key), kill(kill), t(t) {}
   bool operator==(const Pos &that) const {
     return this->r == that.r && this->c == that.c && this->key == that.key;
   }
+  bool operator<(const Pos &that) const { return this->t > that.t; }
 };
 
-char n, m;
-
-bool is_expandable(char x, char y, char key, char died) {
-  if (x < 0 || n <= x || y < 0 || n <= y) return false;
-  if (map[x][y] == '#' || flag[x][y][key][died]) return false;
-  return true;
-}
-
 int main() {
+  int n, m;
   while (scanf("%d %d", &n, &m) != EOF) {
     if (n == 0 && m == 0) break;
     Pos sun, tang;
     int s = 0;
-    for (char i = 0; i < n; i++) {
+    for (int i = 0; i < n; i++) {
       scanf("%s", map[i]);
-      for (char j = 0; j < n; j++) {
+      for (int j = 0; j < n; j++) {
         if (map[i][j] == 'T') {
           tang.r = i;
           tang.c = j;
@@ -59,12 +51,12 @@ int main() {
         }
       }
     }
-    queue<Pos> q;
+    priority_queue<Pos> q;
     q.push(sun);
     memset(flag, 0, sizeof(flag));
-    flag[sun.r][sun.c][0][0] = true;
+    flag[sun.r][sun.c][0] = true;
     while (!q.empty()) {
-      Pos &cur = q.front();
+      Pos cur = q.top();
       q.pop();
       if (cur == tang) {
         tang.t = cur.t;
@@ -73,6 +65,28 @@ int main() {
       for (int i = 0; i < 4; i++) {
         int nx = cur.r + dx[i];
         int ny = cur.c + dy[i];
+        if (nx < 0 || n <= nx || ny < 0 || n <= ny) continue;
+        char grid = map[nx][ny];
+        if (grid == '#') continue;
+        if (grid == 'S') {
+          if (flag[nx][ny][cur.key]) continue;
+          if (cur.kill & (1 << snake[nx][ny]))
+            q.emplace(nx, ny, cur.key, cur.kill, cur.t + 1);
+          else
+            q.emplace(nx, ny, cur.key, cur.kill | (1 << snake[nx][ny]),
+                      cur.t + 2);
+          flag[nx][ny][cur.key] = true;
+        } else {
+          if (!flag[nx][ny][cur.key]) {
+            q.emplace(nx, ny, cur.key, cur.kill, cur.t + 1);
+            flag[nx][ny][cur.key] = true;
+          }
+          if ('1' <= grid && grid <= '9' && grid - '0' == cur.key + 1 &&
+              !flag[nx][ny][grid - '0']) {  // Get key
+            q.emplace(nx, ny, grid - '0', cur.kill, cur.t + 1);
+            flag[nx][ny][grid - '0'] = true;
+          }
+        }
       }
     }
     if (tang.t == -1)