10114 - Loansome Car Buyer

[Per]

For the second test case, why isn't the answer "0 months."? (At this time the buyer owes 12*500 = 6000 dollars, but has a car worth 9974.99 dollars.)

For the third test case, how can the answer be 49? After 49 months, the buyer still owes (60-49)*2400 = 26400 dollars, almost as much as the car was worth from the beginning, and more than it was worth even after one month?

I'm guessing there is some subtle sentence in the problem statement that I'm missing, and I'd be thankful if someone could help me out.

[Whinii F.]

It's a late reply but from the ranklist of the problem I see you not listed yet.

For the second test case, the total amount of loan is not 6000. $500 is the down payment, which were paid already, immediately after borrowing the money. The remaining loan to be paid is $9999.99 and it will be paid in 12 months. So your car's value is 9999.99 + 500 = 10499.99 and you owe 9999.99. The first depreciation in Month 0 causes the car to be 9974.9905 and that's still lesser than the loan.

But after the first month the car goes 9476.24 and you pay off 833.3325 so your remaining loan is 9166.66. So CAR > LOAN.

Hope I helped!

[Per]

Ah, I had completely misunderstood the meaning of the downpayment!

Thanks a lot!

[bonsu]

Hi can anyone point me in the right direction, I'm not sure why i'm getting wrong answer? It passes on given test cases

Code: Select all

#include <fstream>
#include <map>
#include <iostream>

using namespace std;

int main()
{
    // ifstream in("loan.in");
    // ofstream out("loan.out");

    int duration;
    double deposit, amount, n_records;
    int month;
    while (cin >> duration >> deposit >> amount >> n_records) {
        // cout << duration << " " << deposit << " " << amount << " " << n_records << endl;
        if (duration < 0) break;
        double repayment = amount / duration;
        int mth, rcount = 0;
        double rate, owed, car_worth = amount+deposit;
        map<int, double> records;
        for (int i = 0; i < n_records; ++i) {
            cin >> mth >> rate;
            // cout << mth << " " << rate << endl;
            records[mth] = rate;
        }
        // cout << "r0: " << records[0] << endl;

        mth = 0; rate = records[0];
        //cout << duration << deposit << amount  << n_records << endl;
        for (int i = 0; i < duration; ++i) {
            owed = amount-(repayment*(i));
            if (owed < 0) break;
            // cout << mth << endl;
            if ((rcount < n_records)) {
                // cout << "here" << endl;
                // cout << i << endl;
                // mth = i;
                map<int,double>::iterator it = records.find(i);
                if (it != records.end()) {
                    // cout << "here" << endl;
                    rate = it->second;
                    ++rcount;
                }
            }
            car_worth = car_worth - (car_worth*rate);
            // cout << "month: " << i << " rate: " << rate << " car_worth: " << car_worth 
            // << " owed: " << owed << endl;
            // cout << i << ": " << car_worth << endl;
            if (owed < car_worth) {
                month = i;
                break;
            }
            // ++mth;
        }
        if (month > 1)
            cout << month << " months" << endl;
        else
            cout << month << " month" << endl;
        records.clear();
        // cout << endl << endl;

    }

    return 0;
}

[brianfry713]

Try input:

Code: Select all

100 0 75000 2
0 .10
99 .5
-1 0 0 0

AC output:

Code: Select all

100 months

[jiayeli]

Whinii's post is helpful.
thank you

[fazel]

hi guys

my code passed two testcases in problem and the one in here , but i'm still getting WA

Code: Select all

#include <iostream>
#include <vector>
#include <iterator>

using namespace std ;

int main ()
{
	freopen("in.txt", "r",stdin);
	int duration;
	cin>>duration;
	vector< double > deprice;
	while (duration >0)
	{
		int numchangedeprice;
		double owed , val ,loan , price ;
		cin>>loan>>price>>numchangedeprice;
		owed =price;
		val = price+loan ;
		int j,i, a[100];
		double b[100];
		cin>>a[0]>>b[0];
		for ( i=1 ; i<numchangedeprice ; i++)
		{
			cin>>a[i]>>b[i];
			deprice.insert(deprice.end(),a[i]-a[i-1],b[i-1]);
		}
		deprice.insert(deprice.end(), duration -a[i-1]+1,b[i-1]);
		int t;
		double pay = price / duration;
		for (t =0; t <duration ; t++)
		{

			owed -=pay;
			val = val*(1-deprice[t]);
			//pay = owed / duration;
			if ( owed< val)
				break;

		}
		if (t==0)
			cout <<"1 month"<<endl;
		else
			cout << t+1<<" months"<<endl;
		deprice.clear();

		cin>>duration;
	}
}

[brianfry713]

Don't read from a file. Try the I/O I posted above.

[fazel]

it passes the test that brainfry sent but still gives wrong answer

Code: Select all

#include <iostream>
#include <string>
#include <string.h>
#include <set>
#include <vector>
#include <stdio.h>
#include <map>
#include <stack>
#include <queue>
//#include <
#include <ctime>
#include <stdlib.h>
#include <search.h>
using namespace std ;


int main ()
{
	//freopen("in.txt", "r",stdin);
	//freopen("out.txt", "w", stdout);
	int length, depricecnt;
	double  dpay,loan, a[110] , c[110];
	int b[110];
	cin>>length;
	while (length >0)
	{
		cin>> dpay>> loan>> depricecnt;
		memset(a, 0, sizeof a);
		memset(b, 0, sizeof b);
		memset(c, 0, sizeof c);
		double value = dpay + loan , monthly = loan /length ;
		for(int i =0 ; i<depricecnt;i++)
		{
			cin>>b[i];
			cin>>a[i];
		}
		//fill c array
		b[depricecnt] =length;
		c[0] = a[0];
		//int ii=0;
		a[depricecnt]=a[depricecnt-1];
		for(int i =1; i<=depricecnt; i++)
		{
			for(int t =b[i-1]; t <b[i]; t++)
				c[t] = a[i-1];
		}
		c[length]=a[depricecnt-1];
		/*for(int i=b[depricecnt-1]; i<length; i++)
			c[i] =a[depricecnt-1];*/
		value -= (c[0]*value);
		int t =1;

		for(t =1 ; t <length ; t++)
		{
			value -= (c[t]*value);
			loan -= monthly;	
			if(loan <value)
				break;
	}
		if (t ==1)
			cout<<"1 month"<<endl;
		else
			cout<<t<<" months"<<endl;
		cin>>length;
	}
	//cout<<double(CLOCKS_PER_SEC)/clock();
	
}

[brianfry713]

Input:

Code: Select all

100 74999 1 1
0 .20
-1 0 0 0

AC output:

Code: Select all

0 months

[fazel]

thank u brain fry the problem was with that ,and one other that it should be exactly "0 months" not "0 month".

[f.maru]

Hi
my program answers are wrong but they are logical because i check them.

Code: Select all

#include<iostream>
using namespace std;
int main()
{
          double month, down,loan,numd,d[200]={0};
          while(cin>>month>>down>>loan>>numd)
          {
                          
                          int q;
                          for(int i=0;i<numd;i++)
                          {
                                  cin>>q;
                                  cin>>d[q];
                          }
                          double set;
                          for(int i=0;i<=month;i++)
                          {
                                  if(d[i]==0)
                                  d[i]=set;
                                  else
                                  set=d[i];
                          }
                          bool flag=true;
                          double owe=loan,worth=loan-(loan*d[0]);
                          int ans=0;
                          while(owe>worth)
                          {
                                          ans++;
                                          owe-=down; 
                                          worth=worth-(worth*d[ans]);
                          }
                          cout<<ans<<" months"<<endl;
          }
          
}

and one more thing i think that if 15000 drop 10% we get 13500 not 13950 why in the problem example, it said 13950 ?????

[brianfry713]

The cars initial value is the down payment $500 plus the loan amount $15,000 = $15,500. As the buy drives it off the lot it depreciates to $15,500 * (1.0 - 0.1) = $13,950

[lmky]

I past the test case for 0 months, and all the test cases given in the problem statement, and I getting WA
Are there anymore critical test cases???

[ccsnail]

Try input:

Code: Select all

100 0 75000 2
0 .10
99 .5
-1 0 0 0

AC output:

Code: Select all

100 months

hi, I didn't pass this test case. I want to know why, can you explain for me? thanks.
I think during month 1 to 98, the depreciation is zero. and month 99 and 100, depreciation is 0.5. Right ? Wrong? and My program result for this testcase is 11 months.