Dungeon Game: DP & Greedy, start from the P, keep the health no higher than zero.

Author: DeanChensj

Hard/174_Dungeon-Game.cpp

@@ -0,0 +1,29 @@
+#include "../Header.h"
+
+using namespace std;
+int calculateMinimumHP(vector<vector<int>>& dungeon) {
+    int h = dungeon.size(), w = dungeon[0].size();
+    int **base = new int*[h];
+    for (int i = 0; i < h; i++) base[i] = new int[w];
+    
+    base[h-1][w-1] = dungeon[h-1][w-1] >= 0 ? 0 : -dungeon[h-1][w-1];
+    for (int i = h-2; i >= 0; i--) {
+        base[i][w-1] = base[i+1][w-1] - dungeon[i][w-1];
+        if (base[i][w-1] < 0) base[i][w-1] = 0;
+        
+    }
+    for (int i = w-2; i >=0; i--) {
+        base[h-1][i] = base[h-1][i+1] - dungeon[h-1][i];
+        if (base[h-1][i] < 0) base[h-1][i] = 0;
+    }
+    
+    for (int i = h-2; i >= 0; i--) {
+        for (int j = w-2; j >= 0; j--) {
+            base[i][j] = min(base[i+1][j], base[i][j+1]) - dungeon[i][j];
+            if (base[i][j] < 0) base[i][j] = 0;
+        }
+    }
+    
+    return base[0][0] + 1;
+}
+