can you help me fix my code so it passes alll the tests its failing

import java.util.HashSet;

$//$ Sum of Strings $[30\%]$

$//$DO NOT add additional fields

$//$DO NOT add additional methods

public class Task$2\{$

$//$ DO NOT change this field

private HashSet strings;

$//$ DO NOT change this method

public void setStrings$($HashSet stringSet$)\{$

strings $=$ stringSet;

$\}$

$//$ DO NOT change the signature for this method

$//$ This method does not need to be recursive

public boolean stringSum$()\{$

for$($String string : strings$)\{$

if$($isConstructable$($string$,$ string$))\{$

return true;

$\}$

$\}$

return false;

$\}$

$//$ This method MUST be recursive

$//$ You can change the name and parameters of this method

private boolean isConstructable$($String aim, String initial$)\{$

return isConstructableHelper$($aim$,$ new HashSet$<>(),$ initial$)$;

$\}$

private boolean isConstructableHelper$($String aim, HashSet visited, String initial$)\{$

if $($aim$.$isEmpty$())$ return true;

if $($visited$.$contains$($aim$))$ return false;

visited.add$($aim$)$;

for $($String string : strings$)\{$

if $(!$string.equals$($initial$)$ && aim.startsWith$($string$))\{$

String remaining $=$ aim.substring$($string$.$length$())$;

if $($isConstructableHelper$($remaining$,$ visited, initial$))\{$

return true;

$\}$

$\}$

$\}$

visited.remove$($aim$)$; $//$ Backtrack

return false;

$\}$

$\}$

public class Task$3\{$

$//$ DO NOT change this field

private int$[][]$ map;

$//$ DO NOT change this method

public void setMap$($int$[][]$ grid$)\{$

map $=$ grid;

$\}$

$//$ DO NOT change the signature for this method

$//$ This method does not need to be recursive

public int dig$($int battery$)\{$

int maxGold $=0$;

for $($int col $=0$; col $<$ map$[0].$length; col$++)\{$

maxGold $=$ Math.max$($maxGold$,$ maximumGoldFrom$(0,$ col, battery, new boolean$[$map$.$length$][$map$[0].$length$]))$;

$\}$

return maxGold;

$\}$

private int maximumGoldFrom$($int y$,$ int x$,$ int battery, boolean$[][]$ visited$)\{$

if $($battery $<=0||$ y $<0||$ y $>=$ map.length $||$ x $<0||$ x $>=$ map$[0].$length $||$ visited$[$y$][$x$])\{$

return $0$;

$\}$

visited$[$y$][$x$]=$ true; $//$ Mark cell as visited

int gold $=$ map$[$y$][$x$]$;

$//$ Explore all directions

int maxGold $=0$;

maxGold $=$ Math.max$($maxGold$,$ gold $+$ maximumGoldFrom$($y$,$ x $-1,$ battery $-1,$ visited$))$; $//$ Left

maxGold $=$ Math.max$($maxGold$,$ gold $+$ maximumGoldFrom$($y$,$ x $+1,$ battery $-1,$ visited$))$; $//$ Right

maxGold $=$ Math.max$($maxGold$,$ gold $+$ maximumGoldFrom$($y $+1,$ x$,$ battery $-1,$ visited$))$; $//$ Down

visited$[$y$][$x$]=$ false; $//$ Backtrack

return maxGold;

$\}$

$\}$

@Test

public void StringSumHelper$3()\{$

Task$2$ t$2=$ new Task$2()$;

HashSet strings $=$ new HashSet$<>()$;

strings.add$("")$;

strings.add$("$SEAN$")$;

t$2.$setStrings$($strings$)$;

boolean output $=$ t$2.$stringSum$()$;

assertEquals$($false$,$ output$)$;

$\}$

@Test

public void DigTest$1()\{$

Task$3$ t$3=$ new Task$3()$;

int$[][]$ map $=$ new int$[][]\{$

new int$[]\{0,1,1,0,0\},$

new int$[]\{2,0,0,0,0\},$

new int$[]\{0,0,3,1,0\},$

new int$[]\{1,0,0,1,0\},$

new int$[]\{0,1,0,0,5\}$

$\}$;

t$3.$setMap$($map$)$;

assertEquals$(13,$ t$3.$dig$(6))$;

$\}$

@Test

public void DigTest$2()\{$

Task$3$ t$3=$ new Task$3()$;

int$[][]$ map $=\{$

new int$[]\{2,3,1\},$

new int$[]\{0,0,0\},$

new int$[]\{5,4,3\}$

$\}$;

t$3.$setMap$($map$)$;

assertEquals$(9,$ t$3.$dig$(3))$;

$\}$

public void DigTest$3()\{$

Task$3$ t$3=$ new Task$3()$;

int$[][]$ map $=\{$

new int$[]\{1,3,1,4\},$

new int$[]\{0,2,5,0\},$

new int$[]\{1,0,2,3\}$

$\}$;

t$3.$setMap$($map$)$;

assertEquals$(21,$ t$3.$dig$(5))$;

$\}$

@Test

public void DigTest$5()\{$

Task$3$ t$3=$ new Task$3()$;

int$[][]$ map $=\{$

new int$[]\{1,2,3\},$

new int$[]\{4,5,6\},$

new int$[]\{7,8,9\}$

$\}$;

t$3.$setMap$($map$)$;

assertEquals$(45,$ t$3.$dig$(6))$;

$\}$

all these are failing DigTest$1()$ org.opentest$4$j$.$AssertionFailedError: Expected :$13$ Actual :$7$ DigTest$2()$ org.opentest$4$j$.$AssertionFailedError: Expected :$9$ Actual :$7$ DigTest$3()$ org.opentest$4$j$.$AssertionFailedError: Expected :$21$ Actual :$15$ DigTest$5()$ org.opentest$4$j$.$AssertionFailedError: Expected :$45$ Actual :$37$ StringSumHelper$3()$ org.opentest$4$j$.$AssertionFailedError: Expected :false Actual :true