11292 - Dragon of Loowater

[scott1991]

hi. Has anyone(with an ac code) got any I/O they could post here so people can check to see if they are getting things right? (people = me)cheers. Scott

[alamgir kabir]

Take this input and I think this will be helpful for u.
knight or dragon's diameter will be long so use data type long.
Input:
2 4
7
2
4
3
1
2
2 4
7
2
2
1
8
5
1 1
2
2
1 1
1
2
3 5
5
6
1
2
3
4
5
1
1 1
2
1
2 10
1234567
2345
12345610
1
123
23564
123456
123
2
3
2
1
0 0
output:
Loowater is doomed!
10
2
2
Loowater is doomed!
Loowater is doomed!
12369174

[scor_k]

#include<stdio.h>

long head[20009],knight[20009];

long sort(long a[],long n)
{
long i,j,k,b=0;
for(i=0;i<n-1;i++)
for(j=0;j<n-i-1;j++)
if(a[j]>a[j+1])
{
b++;
k=a[j];
a[j]=a[j+1];
a[j+1]=k;
}

}













int main()
{

long m,n,x,y,k,a,b,sum,cnt;

while(scanf("%ld %ld",&m,&n)==2)
{

if(m==0 && n==0)
break;

for(x=0;x<m;x++)
scanf("%ld",&head[x]);

for(y=0;y<n;y++)
scanf("%ld",&knight[y]);



sort(head,m);
sort(knight,n);

sum=0;
cnt=0;


for(a=0;a<m;a++)
{
for(b=0;b<n;b++)
{

if(head[a]<=knight)
{ cnt++;
sum=sum+knight;
b=n;
}


}
}


if(m>n || cnt<m)
{
printf("Loowater is doomed!\n");

}
else
printf("%ld\n",sum);




}return 0;

}

[Shafaet_du]

Nice easy problem. Here's my algo:
1. sort the dragons and knights(ascending). stored the knight is stl list and dragons in simple array.
2. for each dragon ran a linear search through knights until a knight whose height is equal or greater than diameter of current knight is found.
3. remove the knight using built in erase function and added the height with sum
4. if suitable knight cant be found answer is doomed.

my code took .256 sec. you can use binary search for bettter performance.

[plamplam]

Damn the input contains negative numbers...beware....I got 4 Wrong Answers because of this. Although I think this is very illogical as n = number of heads and m = number of knights so n and m can't be less than 0. Nevertheless, not all problems should seem to be logical I guess.

[dideler]

@ scor_k I tried your solution and got TLE.

I've tried my own solution with integers, longs, checking for edge cases, but still get WA.
(It shouldn't even make a difference using longs or ints, because with most compilers int has the same size and representation as a long.)
The sample test case and the test case posted in this thread work fine .

Code: Select all

/**
 * 11292 - Dragon of Loowater
 * author: Dennis Ideler
 * category: greedy
 */

#include <algorithm>
#include <iostream>
using namespace std;

int main()
{
  // knight height >= head diameter
  // wage = height
  // minimize expenses (i.e. choose shortest knights possible)

  long n, m; // n = dragon heads, m = knights
  while (cin >> n >> m)
  {
    if (n == 0 && m == 0) break;

    long dd[n]; // dragon diameter
    for (long i = 0; i < n; i++)  // read diameter of each dragon head
      cin >> dd[i];

    long kh[m]; // knight height
    for (long i = 0; i < m; i++)  // read height of each knight
      cin >> kh[i];

    if (n <= 0)
    {
      cout << "0" << endl;
    }
    if (n > m || m <= 0)
    {
      cout << "Loowater is doomed!" << endl;
      continue;
    }

    // find minimum number of gold coins needed for the job
    sort(dd, dd + n);
    sort(kh, kh + m); // sorted data makes comparison easier

    long gold = 0;
    long j = 0;
    bool doom = false;
    for (long i = 0; i < n; ++i) // for each dragon head
    {
      for (; j < m; ++j) // for each knight
      {
        if (dd[i] <= kh[j])  // knight is capable
        {
          gold += kh[j];  // assign knight
          break; // go to next dragon head
        }
        if (j == m-1) // no knight capable
        {
          doom = true;
          cout << "Loowater is doomed!" << endl;
        }
      }
    }
    if (!doom)  // if all dragon heads slain
      cout << gold << endl;
  }

  return 0;
}

[mostafiz93]

this problem can be solved easily with the complexity of only sorting. after sorting knight and dragon array, try to find the dragon that can be slain by minimum height knight.

if all dragon can not be slain with the provided knights, loowater is doomed!

[jsherlock]

This code is giving me a wrong answer verdict, can somebody help me, I'm just new at programming and learning here will help a lot. Thanks in advance.

Code: Select all

#include <stdio.h>
#include <stdlib.h>
#define max 20000

int compare(const void  * a, const void * b)
{
    return(*(int*)a - *(int*)b);
}

int main(){
    int diameter[max];
    int height[max];
    int drHead = 0;
    int knight = 0;
    int i,j;
    int sum = 0;
    int killed=0;

    while(scanf("%d %d", &drHead, &knight), drHead, knight){
    for(i=0; i<drHead; i++)
      scanf("%d", &diameter[i]);
      
    for(i=0; i<knight; i++)
      scanf("%d", &height[i]);
      
      qsort(diameter, drHead, sizeof(int), compare);
      qsort(height, knight, sizeof(int), compare);
      
      for(i=0; i<knight; i++)
        for(j=0; j<drHead; j++)
        {
          if (height[i] >= diameter[i])
	         diameter[i] = 0;
        }
	         
    for(i=0; i< drHead; i++)
      sum = sum + diameter[i];
	         
    if(sum == 0)
      killed = 1;
    else
      killed = 0;
      
    if(knight < drHead || killed == 0)
        printf("Loowater is doomed!\n");
    else
    {
      for(i=0;i<drHead;i++)
        sum = sum + height[i];
        printf("%d\n", sum);
      }   
    }

    return 0;
}

[brianfry713]

see http://acm.uva.es/board/viewtopic.php?t=26190

[uDebug]

Replying to follow the thread.

[infinia249]

Testcase-wise, using uDebug's Random Input, my code outputted the correct answer. But the OJ stated it as Wrong Answer. What could be wrong here?

Code: Select all

#include <iostream>
#include <algorithm>

using namespace std;

int main () {
	int n, m; 
	long hd[20000], kh[20000];
	while ( cin >> n >> m && n != 0 && m != 0 ) {
		long pay = 0;
		for ( int i = 0; i < n; i++ ) {
			cin >> hd[i];
		}
		sort( hd, hd + n );
		for ( int i = 0; i < m; i++ ) {
			cin >> kh[i];
		}
		sort ( kh, kh + m );
		if ( n > m ) {
			cout << "Loowater is doomed!" << endl;
			continue;
		}
		int flag = 0, headcount = n;
		for ( int i = 0; i < n; i++ ) {
			for ( int j = flag; j < m; j++ ) {
				if ( kh[j] >= hd[i] ) {
					flag = j;
					pay += kh[j];
					headcount--;
					break;
				}
			}
		}
		if ( headcount > 0 ) {
			cout << "Loowater is doomed!" << endl;
		}
		else {
			cout << pay << endl;
		}
	}
	return 0;
}