HackerRank_Solutions/Problem Solving (Algorithms)/RedKnightsShortestPath.java at master · Spartans3/HackerRank_Solutions · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class RedKnightsShortestPath {
//	https://www.hackerrank.com/challenges/red-knights-shortest-path/problem
    // Complete the printShortestPath function below.
    static void printShortestPath(int n, int x1, int y1, int x2, int y2) {
        // Print the distance along with the sequence of moves.
        if(Math.abs(x1-x2) % 2 != 0) {
            System.out.println("Impossible");
            return;
        }


        int moves = 0;
        List<String> listDistance = new ArrayList<String>();


        while(x1 != x2 || y1 !=y2) {

            if(x1>x2) {
                if(y1>y2) {
                    y1 -=1;
                    x1 -=2;
                    listDistance.add("UL");
                }else {
                    y1 +=1;
                    x1 -=2;
                    listDistance.add("UR");
                }

                moves++;
                if(x1 == x2 && y1 == y2) {
                    printResult(listDistance, moves);
                    return;
                }
            }else if(x1<x2) {
                if(y1>y2) {
                    y1 -=1;
                    x1 +=2;
                    listDistance.add("LL");
                }else {
                    y1 +=1;
                    x1 +=2;
                    listDistance.add("LR");
                }

                moves++;
                if(x1 == x2 && y1 == y2) {
                    printResult(listDistance, moves);
                    return;
                }
            }else {
                if(Math.abs(y1-y2) %2 == 1) {
                    System.out.println("Impossible");
                    return;
                }

                if(y1<y2) {
                    y1 += 2;
                    listDistance.add("R");
                }else if(y1>y2) {
                    y1 -=2;
                    listDistance.add("L");
                }else {
                    printResult(listDistance, moves);
                    return;
                }
                moves++;

                if(x1 == x2 && y1 == y2) {
                    printResult(listDistance, moves);
                    return;
                }

            }

        }
    }

    static void printResult(List<String> list, int moves) {
        String str = "";


        if(list.contains("LR")) {
            Comparator<String> c = new Comparator<String>() {

                @Override
                public int compare(String o1, String o2) {
                    if(o1.equals("LR") && o2.equals("LL"))
                        return -1;
                    else if(o1.equals("LL") && o2.equals("LR"))
                        return 1;
                    else if(o1.equals("R") && o2.equals("LR"))
                        return -1;
                    else if(o1.equals("LR") && o2.equals("R"))
                        return 1;
                    else
                        return 0;

                }
            };

            Collections.sort(list, c);
        }

        for (String step : list) {
            str += step + " ";
        }
        System.out.println(moves);
        System.out.println(str.trim());
    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        int n = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        String[] i_startJ_start = scanner.nextLine().split(" ");

        int i_start = Integer.parseInt(i_startJ_start[0]);

        int j_start = Integer.parseInt(i_startJ_start[1]);

        int i_end = Integer.parseInt(i_startJ_start[2]);

        int j_end = Integer.parseInt(i_startJ_start[3]);

        printShortestPath(n, i_start, j_start, i_end, j_end);

        scanner.close();
    }
}