674 - Coin Change

[58050zz]

Try to read this book when u will free. It will help you much. Greedy most probably in chapter 16.

Greedy is in ch16
do i use Greedy to slove this?


to sohel:
my code is not AC is TLE^^

[sohel]

to sohel:
my code is not AC is TLE^^

I was not refering to your code.

[58050zz]

Hi,
From your code it looks like you are using brute force. And that should obviously get TLE.

Implementation of DP:
1) declare an int array of size 7500
2) initialize all the elements with 0
3) set Array[0] = 1; --- because there is only one way of making zero ie
'by not choosing any coin'.

4) for every coin run a loop from j = 1 to 7500
set Array[ coinvalue + j] += Array[j];
5) END

Hope it helps.

i use ur algorithm and slove ok for 674
but WA for 147
can u tell me why?

[58050zz]

do ur algorithm here

==output here
while(cin>>target)
{
cout.width(6);
cout.precision(2);
cout<<target;
if(target==0)return 0;
int tar=(int)(target*100);

cout<<setw(17)<<setiosflags(ios::right)
<<Array[tar]<<endl;
}

[sohel]

while(cin>>target)
{
cout.width(6);
cout.precision(2);
cout<<target;
if(target==0)return 0;
int tar=(int)(target*100);

cout<<setw(17)<<setiosflags(ios::right)
<<Array[tar]<<endl;
}

I think the error could be in handling the conversion of floating point number to integer.
There are other posts related to this problem.
.. 5.00 * 100 is not equal to 500, instead it is 499.

try to convert int tar = (int)(target*100) to
int tar = (int)(target*100 + 0.001 ).

Hope it helps.

[58050zz]

thank you ,
for your help
i get AC

[devilshit]

I don't know why I get the problem. Please help.

Code: Select all

while(scanf("%d", &n) != 0)
        printf("%d\n", dp[n]);

dp[n] = storing the number of way(int) when there is n-cent

This code works fine on my machine(winxp, visual c++ 6.0)

[zhuo]

I've tried a lot of test data, but I still got WA.
Why?? ~ help, please

Code: Select all

#include<stdio.h>/* 674 357 147*/

int main(){
	int a[30001][4],t;
	int i,tol,n;

	for(i=0;i<5;i++){
		a[i][0]=0; 
		a[i][1]=0;
		a[i][2]=0;
		a[i][3]=0;
	}
	tol=4;
	
	while( scanf("%d",&n)!=EOF ){
		
		if(n>tol){
			for( ; tol<=n ;tol++){
				if( tol>=50)
					a[tol][0]=a[tol-50][0]+a[tol-50][1]+a[tol-50][2]+a[tol-50][3]+1;
				else
					a[tol][0]=0;

				if( tol>=25)
					a[tol][1]=a[tol-25][1]+a[tol-25][2]+a[tol-25][3]+1;
				else
					a[tol][1]=0;

				if( tol>=10)
					a[tol][2]=a[tol-10][2]+a[tol-10][3]+1;
				else
					a[tol][2]=0;

				if( tol>=5)
					a[tol][3]=a[tol-5][3]+1;
				else
					a[tol][3]=0;
			}
		}
		
		t=a[n][0]+a[n][1]+a[n][2]+a[n][3]+1;
		printf("%d\n",t);
		/*if(t!=1)
			printf("There are %d ways to produce %d cents change. \n",t,n);
		else	
			printf("There are 1 way to produce %d cents change. \n",n);*/
		
	}
	return 0;
}

[mamun]

Input

Code: Select all

5
6

Output

Code: Select all

2
2

[zhuo]

I got accepted . I done a stupid mistake.
Thanks a lot.

[Rocklets]

why this code have TLE?

Code: Select all

edited afer AC

[tanvir_cse]

Hi,Iam suffering a lot, and need an algorithm badly. Anybody Help me

Code: Select all

#include<stdio.h>
#include<iostream.h>
#include<string.h>

int cent_1(int mon);
int cent_5(int mon);
int cent_10(int mon);
int cent_25(int mon);
int cent_50(int mon);

int count=0;
 
int main(void)
{
	int cent, sum;
	while(scanf("%d",&cent)!=EOF)
	{
		count=0;
		if(cent>=1 && cent<=4)
		{
			printf("%d\n",cent_1(cent));
		}
		if(cent>=5 && cent<=9)
		{
			sum=0;
			if(cent==5)
				sum=1;
			sum+=cent_1(cent);
			sum+=cent_5(cent);
			printf("%d\n",sum);
		}
		if(cent>=10 && cent<=24)
		{
			sum=0;
			if(cent==10)
				sum+=1;

			sum+=cent_1(cent);
			sum+=cent_5(cent);
			sum+=cent_10(cent);

			printf("%d\n",sum);
		}
		if(cent>=25 && cent<=49)
		{
			sum=0;
			if(cent==25)
				sum+=1;

			sum+=cent_1(cent);
			sum+=cent_5(cent);
			sum+=cent_10(cent);			
			sum+=cent_25(cent);

			printf("%d\n",sum);
		}
		if(cent>=50)
		{
			sum=0;
			if(cent==50)
				sum+=1;

			sum+=cent_1(cent);
			sum+=cent_5(cent);
			sum+=cent_10(cent);			
			sum+=cent_25(cent);
			sum+=cent_50(cent);

			printf("%d\n",sum);
		}
	}
}



int cent_1( int mon)
{

	if(mon==0)
		return 0;

	return 1;

}


int cent_5( int mon)
{
	int i,m,t=0,temp;

	if(mon==0)
		return 0;

	m=mon/5;
	for(i=m; i>0; i--)
	{
		temp=mon-5*i;
		t=t+cent_1(temp);
	}

	return t;

}



int cent_10( int mon)
{
	int i,m,t=0,temp;
	if(mon==0)
		return 0;

	m=mon/10;
	for(i=m; i>0; i--)
	{
		temp=mon-10*i;
		t=t+cent_1(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-10*i;
		t=t+cent_5(temp);
	}

	return t;
}


int cent_25( int mon)
{
	int i,m,t=0,temp;
	if(mon==0)
		return 0;

	m=mon/25;
	for(i=m; i>0; i--)
	{
		temp=mon-25*i;
		t=t+cent_1(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-25*i;
		t=t+cent_5(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-25*i;
		t=t+cent_10(temp);
	}

	return t;
}

int cent_50( int mon)
{
	int i,m,t=0,temp;
	if(mon==0)
		return 0;

	m=mon/50;
	for(i=m; i>0; i--)
	{
		temp=mon-50*i;
		t=t+cent_1(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-50*i;
		t=t+cent_5(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-50*i;
		t=t+cent_10(temp);
	}

	for(i=m; i>0; i--)
	{
		temp=mon-50*i;
		t=t+cent_25(temp);
	}

	return t;
}

[mimi]

I got tle. Will anybody see my code and tell me where i am wrong. Thanks in advance.
Here is my code:

import java.io.*;

public class Main
{
public static void main(String[] args) throws IOException
{
BufferedReader vhod = new BufferedReader(new InputStreamReader(System.in));
while(true)
{
int n = Integer.parseInt(vhod.readLine());
System.out.println(coinchange(n));
}
}
public static int coinchange(int n)
{
int tab[]=new int[7490];
int coin[] = new int[5];
coin[0]=1;
coin[1]=5;
coin[2]=10;
coin[3]=25;
coin[4]=50;
for(int i = 0; i < 7490; i++)
{
tab = 0;
tab[0] = 1;
}
for(int i = 0; i < 5; i++)
{
int c = coin;
for(int j = c; j < 7490; j++)
{
tab[j] += tab[j-c];
}
}
return tab[n];
}
}

[mf]

Your code recomputes a big array (int tab[]=new int[7490]) for every case.
Of course this is making your program many thousands times slower than it could be if you computed this array only once, what'd you expect? Compiler's not smart enough to move the computation of that array out of the main loop for you.

[mimi]

Can you please tell me how to change my program to compute this array only once Thanks