Add solution 174.

Author: javadev

src/Algorithms/0174.dungeon-game/dungeon-game.php

@@ -0,0 +1,33 @@
+class Solution {
+
+    private $dp;
+    private $visited;
+
+    /**
+     * @param Integer[][] $dungeon
+     * @return Integer
+     */
+    function calculateMinimumHP(&$dungeon) {
+        $dp = array_fill(0, count($dungeon), array_fill(0, count($dungeon[0]), 0));
+        $visited = array_fill(0, count($dungeon), array_fill(0, count($dungeon[0]), false));
+        $val = self::solve($dungeon, 0, 0);
+        return $val >= 1 ? 1 : 1-$val;
+    }
+    
+    function solve(&$dungeon, $i, $j) {
+        if($i == count($dungeon)-1 && $j == count($dungeon[0])-1) return $dungeon[$i][$j];
+        if($i == count($dungeon)) return -2147483647;
+        if($j == count($dungeon[0])) return -2147483647;
+        
+        if($visited[$i][$j]) {
+            return $dp[$i][$j];
+        }
+        
+        $val = min($dungeon[$i][$j] + max(self::solve($dungeon, $i+1, $j), self::solve($dungeon, $i, $j+1)), $dungeon[$i][$j]);
+        
+        $dp[$i][$j] = $val;
+        $visited[$i][$j] = true;
+        
+        return $val;
+    }
+}