POJ 1011 Sticks
2014-03-11 10:57
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Description
George took sticks of the same length and cut them randomly until all parts became at most 50 units long. Now he wants to return sticks to the original state, but he forgot how many sticks he had originally and how long they were originally. Please help him and design a program which computes the smallest possible original length of those sticks. All lengths expressed in units are integers greater than zero.
Input
The input contains blocks of 2 lines. The first line contains the number of sticks parts after cutting, there are at most 64 sticks. The second line contains the lengths of those parts separated by the space. The last line of the file contains zero.
Output
The output should contains the smallest possible length of original sticks, one per line.
Sample Input
Sample Output
/*
* java实现
*/
import java.util.LinkedList;
import java.util.Scanner;
public class Main {
private final byte N;
private byte[] segments;
private boolean[] marked;
private int originShortestLength;
private int sumLength;
Main(byte n, byte[] segements) {
this.N = n;
this.segments = sort(segements);
originShortestLength = 0;
for(int i = 0; i < N; i++)
sumLength += this.segments[i];
}
public byte[] sort(byte[] array) {
for(int i = 1; i < array.length; i++) {
for(int j = i; j > 0 && array[j] > array[j-1]; j--) {
byte temp = array[j];
array[j] = array[j-1];
array[j-1] = temp;
}
}
return array;
}
public int originShortestLength() {
return originShortestLength;
}
@SuppressWarnings("unused")
public boolean hasOriginShortestLength() {
byte n = (byte) (N - 1);
//boolean find = true;
for(; n > 0; n--) {
if(sumLength%n == 0) {
int average = sumLength/n;
//byte base = (byte) ((byte) + (byte)segments[N-1]);
if(segments[0] > average)
continue;
marked = new boolean
;
byte start;
for(int i = 0; i < n; i++) {
int sum = 0;
for(start = 0; start < N; start++)
if(!marked[start]) {
marked[start] = true;
sum = segments[start];
break;
}
if(!dfs(average, sum, start, (byte)(N-1)))
return false;
}
originShortestLength = average;
return true;
}
}
return false;
}
public boolean dfs(int average, int sum, byte low, byte high) {
if(low >= high)
return false;
if(marked[high]){
if(dfs(average, sum, low, (byte) (high-1)))
return true;
}
else if(sum + segments[high] > average)
return false;
else if(sum + segments[high] < average) {
marked[high] = true;
if(!dfs(average, sum + segments[high], low, (byte) (high-1))) {
marked[high] = false;
if(dfs(average, sum, low, (byte) (high-1)))
return true;
}
else
return true;
}
else {
marked[high] = true;
return true;
}
return false;
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
LinkedList<Integer> results = new LinkedList<Integer>();
while(in.hasNext()) {
byte n = in.nextByte();
if(n == 0)
break;
byte[] segements = new byte
;
for(int i = 0; i < n; i++) {
segements[i] = in.nextByte();
}
Main m = new Main(n, segements);
if(m.hasOriginShortestLength())
results.add(m.originShortestLength());
else
System.out.println("no answer");
}
for(int b : results)
System.out.println(b);
}
}
George took sticks of the same length and cut them randomly until all parts became at most 50 units long. Now he wants to return sticks to the original state, but he forgot how many sticks he had originally and how long they were originally. Please help him and design a program which computes the smallest possible original length of those sticks. All lengths expressed in units are integers greater than zero.
Input
The input contains blocks of 2 lines. The first line contains the number of sticks parts after cutting, there are at most 64 sticks. The second line contains the lengths of those parts separated by the space. The last line of the file contains zero.
Output
The output should contains the smallest possible length of original sticks, one per line.
Sample Input
9 5 2 1 5 2 1 5 2 1 4 1 2 3 4 0
Sample Output
6 5
/*
* java实现
*/
import java.util.LinkedList;
import java.util.Scanner;
public class Main {
private final byte N;
private byte[] segments;
private boolean[] marked;
private int originShortestLength;
private int sumLength;
Main(byte n, byte[] segements) {
this.N = n;
this.segments = sort(segements);
originShortestLength = 0;
for(int i = 0; i < N; i++)
sumLength += this.segments[i];
}
public byte[] sort(byte[] array) {
for(int i = 1; i < array.length; i++) {
for(int j = i; j > 0 && array[j] > array[j-1]; j--) {
byte temp = array[j];
array[j] = array[j-1];
array[j-1] = temp;
}
}
return array;
}
public int originShortestLength() {
return originShortestLength;
}
@SuppressWarnings("unused")
public boolean hasOriginShortestLength() {
byte n = (byte) (N - 1);
//boolean find = true;
for(; n > 0; n--) {
if(sumLength%n == 0) {
int average = sumLength/n;
//byte base = (byte) ((byte) + (byte)segments[N-1]);
if(segments[0] > average)
continue;
marked = new boolean
;
byte start;
for(int i = 0; i < n; i++) {
int sum = 0;
for(start = 0; start < N; start++)
if(!marked[start]) {
marked[start] = true;
sum = segments[start];
break;
}
if(!dfs(average, sum, start, (byte)(N-1)))
return false;
}
originShortestLength = average;
return true;
}
}
return false;
}
public boolean dfs(int average, int sum, byte low, byte high) {
if(low >= high)
return false;
if(marked[high]){
if(dfs(average, sum, low, (byte) (high-1)))
return true;
}
else if(sum + segments[high] > average)
return false;
else if(sum + segments[high] < average) {
marked[high] = true;
if(!dfs(average, sum + segments[high], low, (byte) (high-1))) {
marked[high] = false;
if(dfs(average, sum, low, (byte) (high-1)))
return true;
}
else
return true;
}
else {
marked[high] = true;
return true;
}
return false;
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
LinkedList<Integer> results = new LinkedList<Integer>();
while(in.hasNext()) {
byte n = in.nextByte();
if(n == 0)
break;
byte[] segements = new byte
;
for(int i = 0; i < n; i++) {
segements[i] = in.nextByte();
}
Main m = new Main(n, segements);
if(m.hasOriginShortestLength())
results.add(m.originShortestLength());
else
System.out.println("no answer");
}
for(int b : results)
System.out.println(b);
}
}
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