CodingGame - Shadows of the Knight - Episode 1思路

Codingame一道中等难度的题目

要求

Knight会获得以当前位置为坐标中心的导航指示(U, UR, R, DR, D, DL, L or UL)

• U -> Up
• D -> Down
• R -> Right
• L -> Left
  根据指示到达目标点

思路

应用了对分查找，大量减少猜测范围。

代码

import java.util.*;
import java.io.*;
import java.math.*;

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/
class Player {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int W = in.nextInt(); // width of the building.
        int H = in.nextInt(); // height of the building.
        int N = in.nextInt(); // maximum number of turns before game over.
        int X0 = in.nextInt();
        int Y0 = in.nextInt();
        int startX = 0,endX = W-1,middleX = -1;
        int startY = 0,endY = H-1,middleY = -1;
        System.err.println(W+" "+H);
        // game loop
        while (true) {
            String bombDir = in.next(); // the direction of the bombs from batman's current location (U, UR, R, DR, D, DL, L or UL)
            if(bombDir.contains("U")){
                if(middleY == -1)
                    endY = Y0 - 1;
                else
                    endY = middleY-1;
            }
            else if(bombDir.contains("D")){
                if(middleY == -1)
                    startY = Y0 + 1;
                else
                    startY = middleY+1;
            }
            if(bombDir.contains("R")){
                if(middleX == -1)
                    startX = X0 + 1;
                else
                    startX = middleX+1;
            }
            else if(bombDir.contains("L")){
                if(middleX == -1)
                    endX = X0 - 1;
                else
                    endX = middleX-1;
            }
            middleX = getMiddle(startX,endX);
            middleY = getMiddle(startY,endY);
            // Write an action using System.out.println()
            // To debug: System.err.println("Debug messages...");


            // the location of the next window Batman should jump to.
            System.out.println(middleX+" "+middleY);
        }
    }
    
    public static int getMiddle(int start,int end){
        return (start+end)/2;
    }
}

后续修正

突然发现之前没有提交，在正式提交时发现塔的那一关未达成，于是在第一次确定搜索范围时，去除了原先站的位置。于是达成100%.