Box Stacking Problem

Author: AbhinavSharma24

Dynamic_Programming/BoxStackingProblem.cpp

@@ -0,0 +1,79 @@
+#include<stdio.h> 
+#include<stdlib.h> 
+
+struct Box 
+{ 
+int h, w, d; 
+}; 
+
+int min (int x, int y) 
+{ return (x < y)? x : y; } 
+
+int max (int x, int y) 
+{ return (x > y)? x : y; } 
+
+int compare (const void *a, const void * b) 
+{ 
+	return ( (*(Box *)b).d * (*(Box *)b).w ) - 
+		( (*(Box *)a).d * (*(Box *)a).w ); 
+} 
+
+int maxStackHeight( Box arr[], int n ) 
+{ 
+Box rot[3*n]; 
+int index = 0; 
+for (int i = 0; i < n; i++) 
+{ 
+	rot[index].h = arr[i].h; 
+	rot[index].d = max(arr[i].d, arr[i].w); 
+	rot[index].w = min(arr[i].d, arr[i].w); 
+	index++; 
+
+	rot[index].h = arr[i].w; 
+	rot[index].d = max(arr[i].h, arr[i].d); 
+	rot[index].w = min(arr[i].h, arr[i].d); 
+	index++; 
+
+	rot[index].h = arr[i].d; 
+	rot[index].d = max(arr[i].h, arr[i].w); 
+	rot[index].w = min(arr[i].h, arr[i].w); 
+	index++; 
+} 
+
+n = 3*n; 
+
+qsort (rot, n, sizeof(rot[0]), compare); 
+
+int msh[n]; 
+for (int i = 0; i < n; i++ ) 
+	msh[i] = rot[i].h; 
+
+for (int i = 1; i < n; i++ ) 
+	for (int j = 0; j < i; j++ ) 
+		if ( rot[i].w < rot[j].w && 
+			rot[i].d < rot[j].d && 
+			msh[i] < msh[j] + rot[i].h 
+			) 
+		{ 
+			msh[i] = msh[j] + rot[i].h; 
+		} 
+
+
+int max = -1; 
+for ( int i = 0; i < n; i++ ) 
+	if ( max < msh[i] ) 
+		max = msh[i]; 
+
+return max; 
+} 
+
+int main() 
+{ 
+Box arr[] = { {4, 6, 7}, {1, 2, 3}, {4, 5, 6}, {10, 12, 32} }; 
+int n = sizeof(arr)/sizeof(arr[0]); 
+
+printf("The maximum possible height of stack is %d\n", 
+		maxStackHeight (arr, n) ); 
+
+return 0; 
+}