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Primer problema

Problem Statement

When a web client (like a browser) requests a particular web page, it typically replaces certain characters with escape sequences. For instance, spaces are replaced with "%20". Your task is to reverse this, replacing every escape sequence in the input with the character it represents. Each escape sequence is formatted as "%XX" where XX is the ASCII value of the escaped character in hexadecimal.
Definition

Class:
URLParser
Method:
parse
Parameters:
String
Returns:
String
Method signature:
String parse(String url)
(be sure your method is public)



"%2525"
Returns: "%25"


Mi respuesta

public class URLParser
{
public String parse(String url)
{
String retorna="";
for(int i=0;i {
if(url.charAt(i)=='%')
retorna+=valor(url.charAt(++i),url.charAt(++i));
else retorna+=url.charAt(i);
}
return retorna;
}
char valor(char a, char b)
{

return (char)(hexchar(a)*16+hexchar(b));
}
char hexchar(char a)
{
return (char)(a>='0'&&a<='9'?a-'0':a-'A'+10);
}
}

Segundo problema

Problem Statement

You are given a String[], grid, representing a city where each character in grid is a single city block. Each block will contain a digit representing the relative population on that block. For example, a block containing the digit '6' will contain three times as many people as a block containing the digit '2'. You are also given a String[], stations, containing the locations of all the fire stations within the city. Each element of stations is formatted as "r c" (quotes for clarity only), where r and c represent the row and column, respectively, of the block on which a fire station is located. Character j of element i of grid represents the block at row i, column j. All indices are 0-based.


{"2312",
"0233"}
{"1 1", "1 1"}
Returns: "0 3"
Respuesta

public class NewStation
{
int[][] popu;
int[][] dist;
int[][] temp;
public String location(String[] grid, String[] stations)
{
//Construir matrices
popu= new int[grid.length][grid[0].length()];
dist= new int[grid.length][grid[0].length()];
temp= new int[grid.length][grid[0].length()];

for(int i=0;i for(int j=0;j {
popu[i][j]=(grid[i].charAt(j)-'0');
dist[i][j]=mD(i,j,stations);
}
float avg=(Average(popu,dist));
String[] stations2=new String[stations.length+1];
int r=-1; int c=-1;
for(int k=0;k stations2[k]=stations[k];
for(int a=0;a for(int b=0;b {
stations2[stations.length]=String.valueOf(a)+" "+String.valueOf(b);
for(int i=0;i for(int j=0;j {
temp[i][j]=mD(i,j,stations2);
}
float avg2=Average(popu,temp);
if(avg2 {
avg=avg2;
r=a;
c=b;
}
}
return r==-1?"":String.valueOf(r)+" "+String.valueOf(c);
}

int MD(int r1,int c1, int r2, int c2)
{
return (Math.max(r1,r2)-Math.min(r1,r2))+(Math.max(c1,c2)-Math.min(c1,c2));
}
int mD(int r1, int c1, String[] stations)
{
String aaa[];
int min=1000000;
for(int i=0;i {
aaa=stations[i].split(" ");
min=Math.min(min,MD(r1,c1,Integer.parseInt(aaa[0]),Integer.parseInt(aaa[1])));
}
return min;
}
float Average( int[][] pop, int[][] dis)
{
float total=0,muls=0;
for(int i=0;i for(int j=0;j {
total+=pop[i][j];
muls+=pop[i][j]*dis[i][j];
}
return muls/total;
}
}