Task: Last letter-first letter




Go: package main

import (
    "fmt"
    "strings"
)

var pokemon = `audino bagon baltoy...67 names omitted...`

func main() {
    
    var d []string
    for _, l := range strings.Split(pokemon, "\n") {
        d = append(d, strings.Fields(l)...)
    }
    fmt.Println("searching", len(d), "names...")
    
    for i := range d {
        d[0], d[i] = d[i], d[0]
        search(d, 1, len(d[0]))
        d[0], d[i] = d[i], d[0]
    }
    fmt.Println("maximum path length:", len(ex))
    fmt.Println("paths of that length:", nMax)
    fmt.Print("example path of that length:")
    for i, n := range ex {
        if i%6 == 0 {
            fmt.Print("\n   ")
        }
        fmt.Print(n, " ")
    }
    fmt.Println()
}

var ex []string
var nMax int

func search(d []string, i, ncPath int) {
    
    if i == len(ex) {
        nMax++
    } else if i > len(ex) {
        nMax = 1
        ex = append(ex[:0], d[:i]...)
    }
    
    lastName := d[i-1]
    lastChar := lastName[len(lastName)-1]
    for j := i; j < len(d); j++ {
        if d[j][0] == lastChar {
            d[i], d[j] = d[j], d[i]
            search(d, i+1, ncPath+1+len(d[i]))
            d[i], d[j] = d[j], d[i]
        }
    }
}


Java: 
final class LastLetterFirstLetter {
    static int maxPathLength = 0;
    static int maxPathLengthCount = 0;
    static final StringBuffer maxPathExample = new StringBuffer(500);

    static final String[] names = {"audino", "bagon", "baltoy", "banette",
        "bidoof", "braviary", "bronzor", "carracosta", "charmeleon",
        "cresselia", "croagunk", "darmanitan", "deino", "emboar",
        "emolga", "exeggcute", "gabite", "girafarig", "gulpin",
        "haxorus", "heatmor", "heatran", "ivysaur", "jellicent",
        "jumpluff", "kangaskhan", "kricketune", "landorus", "ledyba",
        "loudred", "lumineon", "lunatone", "machamp", "magnezone",
        "mamoswine", "nosepass", "petilil", "pidgeotto", "pikachu",
        "pinsir", "poliwrath", "poochyena", "porygon2", "porygonz",
        "registeel", "relicanth", "remoraid", "rufflet", "sableye",
        "scolipede", "scrafty", "seaking", "sealeo", "silcoon",
        "simisear", "snivy", "snorlax", "spoink", "starly", "tirtouga",
        "trapinch", "treecko", "tyrogue", "vigoroth", "vulpix",
        "wailord", "wartortle", "whismur", "wingull", "yamask"};

    static void recursive(String[] part, int offset) {
        if (offset > maxPathLength) {
            maxPathLength = offset;
            maxPathLengthCount = 1;
        } else if (offset == maxPathLength) {
            maxPathLengthCount++;
            maxPathExample.setLength(0);
            for (int i = 0; i < offset; i++) {
                maxPathExample.append((i % 5 == 0 ? "\n  " : " "));
                maxPathExample.append(part[i]);
            }
        }
        final char lastChar = part[offset - 1].charAt(part[offset - 1].length()-1);
        for (int i = offset; i < part.length; i++) {
            if (part[i].charAt(0) == lastChar) {
                String tmp = names[offset];
                names[offset] = names[i];
                names[i] = tmp;
                recursive(names, offset+1);
                names[i] = names[offset];
                names[offset] = tmp;
            }
        }
    }

    public static void main(String[] args) {
        for (int i = 0; i < names.length; i++) {
            String tmp = names[0];
            names[0] = names[i];
            names[i] = tmp;
            recursive(names, 1);
            names[i] = names[0];
            names[0] = tmp;
       }
       System.out.println("maximum path length        : " + maxPathLength);
       System.out.println("paths of that length       : " + maxPathLengthCount);
       System.out.println("example path of that length:" + maxPathExample);
    }
}