Calculate the Amount of Money in the box

Given a box of coins, Type of coins inside the box & weight of each type of coin & total weight of the box, you have to find the amount inside the box.


For example: 

             Given a box whose weight is 100 gm while it is empty and 150 gm after we place coins inside the box. If coin types are Rs.2 & Rs.5 with weights 5 gm & 12 gm respectively. 

             Then, the amount inside the box is = Rs.20


Implementation:

#include <stdio.h>
int main()
{
    int T,TW,Q,P,N,i,V[500],W[500],M,Op,count=0,xcount=0,Resx,Resy,Resz,x,y,z,Op1;
    scanf("%d",&T);
    while(T>0)
    {
        scanf("%d%d",&P,&Q);
        TW=Q-P;
        scanf("%d",&N);
        for(i=0;i<N;i++)
        {
            scanf("%d%d",&V[i],&W[i]);
           
        }
        count=0;
        for(i=0;i<N;i++)
        {
            if(TW%(W[i]+W[i+1]+W[i+2])==0)
            {
                Resx=TW/W[i];
                Resy=TW/W[i+1];
                Resz=TW/W[i+2];
                for(x=1;x<=Resx;x++)
                {
                    for(y=1;y<=Resy;y++)
                    {
                        for(z=1;z<=Resz;z++)
                        {
                        if(W[i]*x+W[i+1]*y+W[i+2]==TW)
                        {
                            Op=V[i]*x+V[i+1]*y+V[i+2]*z;
                            xcount++;
                        }   
                        }
                       
                    }
                }
            }
            else
            if(TW%(W[i]+W[i+1])==0||TW%(W[i]+W[i+2])==0)
            {
                Resx=TW/W[i];
                Resy=TW/W[i+1];
                for(x=1;x<=Resx;x++)
                {
                    for(y=1;y<=Resy;y++)
                    {
                        if(W[i]*x+W[i+1]*y==TW)
                        {
                            Op=V[i]*x+V[i+1]*y;
                            xcount++;
                        }
                    }
                }
            }
            else
            if(TW%W[i]==0)
            {
            M=TW/W[i];
            Op1=V[i]*M;
            count++;
            }
           
        }
        T--;
        if(xcount>0&&count>0&&Op<Op1)
        printf("%d\n",Op);
        else if(count>0&&Op1<Op)
        printf("%d\n",Op1);
        else
        printf("Impossible.\n");
       
    }
    return 0;
}

     
INPUT

First line - (T) Number of Testcases
Second line - (P) Weight of an empty box and (Q) Weight of a coin filled box
Third line - (N) Number of Type of coins
Fourth line & Fifth line - (V) Type of coin and (W) Weight of coin

OUTPUT

The minimum amount. If the weight cannot be reached , print "Impossible."

Sample Input

1
100 150
2
2 5
5 12

Sample Output

20