need help with Java coding for North West Corner algorithm

[ytcheng]

:confused:Hi,
I wrote a code to generate a table that reflects the supply of factory and demand of warehouse. here's the data

Factory Supply warehouse demand
Factory 1 100 Warehouse 1 150
Factory 2 200 Warehouse 2 180
Factory 3 300 Warehouse 3 270

I am suppose to write a program that would generate a table which looks like this
100 0 0
50 150 0
0 30 270

where the rows represent the supply and the columns represent the demand. Sum of row 1 equals the supply of factory 1 and so on. The sum of column 1 equals the demand of warehouse 1 and so on. I have attempted to write the program but it is not generating the table that I want. Please point out to me where the problem is and how it can be fix.


public class SD {
public static void main(String []args){
int []s={100,200,300};
int[]d={150,180,270};
System.out.println("s= "+s.length);
System.out.println("d= "+d.length);

int [][]calc=new int[s.length][d.length];
int sums=0;
int sumd=0;
for(int i=0;i<=s.length-1;i++)
{ int totalsupply=s[i];

for(int j=0;j<=d.length-1;j++)
{ int totaldemand=d[j];

if(s[i]<=d[j])
{ calc[i][j]=s[i];
calc[i+1][j]=d[j]-s[i];
calc[0][1]=0;
calc[0][2]=0;
sums+=calc[i][j];
}
System.out.print(calc[i][j]+" ");
}
System.out.println("\n");
}
}
//output I get is this
//s= 3
//d= 3
//100 0 0

//50 80 200

//0 0 70

[gcalvin]

You have your array of arrays and nested loop set up properly. Now when you calculate your cells, you want to work on only the cell calc[i][j] during that iteration of the loop. in pseudocode:

for (each factory)
    for (each warehouse)
        if (remaining demand for this factory can be filled from this warehouse)
            quantity q = remaining demand from this factory
        else
            quantity q = remaining supply in this warehouse
        enter q in this cell
        subtract q from this factory's demand
        subtract q from this warehouse's supply
    next warehouse
next factory

Of course if remaining demand and/or remaining supply is zero, you still go through the steps. Hope that makes sense.

-Gary-