learning golang in hackerrank AI domain https://www.hackerrank.com/domains/ai

bot.go

// Solved 'Bot saves princess' on hackerrank
// https://www.hackerrank.com/challenges/saveprincess
package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

func main() {
	var princessX, princessY int
	var botX, botY int
	var n int

	// Read matrix size.
	fmt.Scanf("%d", &n)

	scanner := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		scanner.Scan()
		line := scanner.Text()
		// Find the princess.
		if i == 0 || i == n-1 {
			if idx := strings.Index(line, "p"); idx != -1 {
				princessX, princessY = idx, i
			}
		}
		// Find the bot.
		if idx := strings.Index(line, "m"); idx != -1 {
			botX, botY = idx, i
		}
	}

	// Move the bot.
	horMove, horDist := "LEFT", botX-princessX
	if horDist < 0 {
		horMove = "RIGHT"
		horDist = -horDist
	}
	for ; horDist > 0; horDist-- {
		fmt.Println(horMove)
	}

	vertMove, vertDist := "UP", botY-princessY
	if vertDist < 0 {
		vertMove = "DOWN"
		vertDist = -vertDist
	}
	for ; vertDist > 0; vertDist-- {
		fmt.Println(vertMove)
	}
}

botclean.go

// Solved 'BotClean Large' on hackerrank
// https://www.hackerrank.com/challenges/botcleanlarge

// Pure greedy algorithm. An improvement would be to calculate
// an optimal path. Score: 54.1
package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
)

func abs(v int) int {
	if v < 0 {
		return -v
	} else {
		return v
	}
}

func main() {
	// Postition of nearest dirt and bot.
	var targetX, targetY int
	var botX, botY int

	// Read bot position.
	fmt.Scanf("%d %d", &botY, &botX)
	// The distance between the bot and the nearest dirt.
	minDist := math.MaxInt32

	scanner := bufio.NewScanner(os.Stdin)
	// Ignore the next line of board size.
	scanner.Scan()
	for y := 0; scanner.Scan(); y++ {
		line := scanner.Text()
		// Find the dirt, and calculate the dist.
		for x, ch := range line {
			if ch == 'd' {
				dist := abs(x-botX) + abs(y-botY)
				if dist == 0 {
					// Clean current dirt.
					fmt.Println("CLEAN")
					return
				} else if dist < minDist {
					minDist, targetX, targetY = dist, x, y
				}
			}
		}
	}

	// Move the bot.
	if botX-targetX > 0 {
		fmt.Println("LEFT")
	} else if botX-targetX < 0 {
		fmt.Println("RIGHT")
	} else if botY-targetY > 0 {
		fmt.Println("UP")
	} else {
		fmt.Println("DOWN")
	}
}