Showing posts with label water jug problem. Show all posts
Showing posts with label water jug problem. Show all posts

Thursday, April 10, 2014

Water jug problem

Problem
You have given a 4-gallon jug and another 3gallon jugs. Neither has measuring marker on it. You have to fill the jugs with water .How can you get exactly 2 gallons of water in to 4gallons. Define set of ordered pairs integers(x,y),such that x=0,1,2,3 or 4 and y=0,1,2 or 3;X represents the number of gallons in 4galoon jug and y represents quantity of water in the 3-gallon jug.Represent the above information in a state space diagram.

Solution

The state space for this problem can be described as
            The set of ordered pair of integers (x, y)
            Such that
             x=0, 1,2,3,4 or 4
             y=0, 1, 2 or 3
x represents the quantity of water in the 4 gallon jug and
y represents the quantity of water in the 3 gallon jug.

The start state is (0, 0)
It is also known as the initial state.
The goal state is (2, n).
n-> it have any value based on the how many gallons in the 3 gallon jug.

For solving this problem we use Production rules

Production rules for Water jug problem
1- (x, y)             (4,y) fill the 4- gallon jug
If x<4

2- (x,y)                (x,3) fill the 3-gallon jug
If x<3

3- (x,y)                (x-d,y) pour some water out of the 4- gallon jug
If x>0

4- (x,y)             (x,y-d) pour some water out of the 3- gallon jug
If y>0

5-(x,y)                 (0,y) empty the 4- gallon jug on the  ground
If x>0

6-(x,y)                  (x,0) empty the 3- gallon jug on the  ground
If y>0d

7- (x,y)                  (4,y-(4-x)) pour water from the 3- gallon jug into the 4-gallon
      If x+y>=4 and y>0                             jug until the 4-gallon jug is full

8- (x,y)                 (x-(3-y),3)) pour water from the 4- gallon jug into the 3-gallon
      If x+y>=3 and x>0                             jug until the 3-gallon jug is full

9- (x,y)                 (x+y,0)  pour all the water from  the 3 -gallon jug into
      If x+y<=4 and y>0                             the 4-gallon jug
10- (x,y)               (0,x+y)  pour all the water from  the 4 -gallon jug into
      If x+y<=3 and x>0                             the 3-gallon jug
11- (0,2)               (2,0)  pour the 2-gallon  from  the 3 -gallon jug into
                                                                 the 4-gallon jug 
12- (2,y)              (0,x)  empty the 2 gallon in the 4 gallon on the ground

One of the Solution to the Water jug problem
Gallons in the                    Gallons in the                   Rule Applied
4- Gallon Jug                       3- gallon
     0                                        0
     0                                        3                                        2
     3                                        0                                        9
     3                                        3                                        2
     4                                        2                                        7
     0                                        2                                        5 or 12
     2                                        0                                        9 or 11

State Space Diagram

Step1
Both jug are empty

Step2
Fill 3 Gallon jug
Step3
Pour water from 3 gallon jug into 4 gallon jug
Step4
fill 3 gallon jug again
Step5
Pour water from 3 gallon jug into 4 gallon jug until it is full
step6
Empty 4 gallon jug
step7 (final Step)
pour water from 3 gallon jug into 4 gallon jug 
That's the answer Good Luck