Erreur d'affichage et de comparaison entre string et un tableau de caractère

#include <SoftwareSerial.h>
#include <string.h>
using namespace std ;
int niveau= 9;
long listmot;
String theme ;
String bonmot ;
unsigned int nbcaracter;
int x = 0;
bool dfaute ;
bool v = false ;
void dvoiture()
{ 
  using namespace std ;
  String Voiture[5][5][2]=
  {
    {"c a r r o s s e r i e ","11","r o u e ","4","p e r m i s ","6","c o u r s e ","6","j a n t e ","5"},
    {"b e r l i n e ","7","c o m p a c t ","7","s i e g e ","5","e c h a p p e m e n t ","11","m o t e u r ","6"},
    {"e m b r a y a g e","9","p o r t e ","5","c o f f r e ","6","r e t r o v i s e u r ","11","d r i f t ","5"},
    {"m a r q u e","6","c a p o t ","5","p l a q u e ","6","i m m a t r i c u l a t i o n ","15","d r a g s t e r ","8"},
    {"f r e i n ","5","r a l l y e ","6","r a d i o ","5","v i t e s s e ","7","a u t o m a t i q u e ","11"}
  };
  Serial.println("Vous devez trouver un mot de ");
  Serial.print(Voiture[niveau][listmot][1]);
  Serial.print(" lettres   !");
  Serial.println("Vous avez le droit de faire 6 fautes pas une de plus !");
  Serial.println(" C'est parti! ");
  nbcaracter = Voiture[niveau][listmot][1].length();
  bonmot = Voiture[niveau][listmot][0];
}
void dmarque()
{
  using namespace std ;
  String Marque[5][5][2]=
  {
    {"s o n y ","4","i n t e l ","5","a p p l e ","5","n o k i a ","5","s a m s u n g ","7"},
    {"m i c r o s o f t ","9","a n d r o i d ","7","l i n u x ","5","n i n t e n d o ","8","b o s e ","4"},
    {"l e n o v o ","6","d e l l ","4","h o n o r ","5","x i a o m i ","6","c o r s a i r ","7"},
    {"m a r s h a l l ","8","k i n g s t o n ","8","t o s h i b a ","7","c i s c o ","5","i b m ","3"},
    {"l o g i t e c h ","8","u b i s o f t ","7","w i k o ","4","p h i l l i p s ","8","n v i d i a ","6"}
  };
  Serial.println("Vous devez trouver un mot de ");
  Serial.print(Marque[niveau][listmot][1]);
  Serial.print(" lettres   !");
  Serial.println("Vous avez le droit de faire 6 fautes pas une de plus !");
  Serial.println(" C'est parti! ");
  nbcaracter = Marque[niveau][listmot][1].length();
  bonmot = Marque[niveau][listmot][0];
}
void dsport()
{ 
  using namespace std ;
  String Sport[5][5][2]=
  {
    {"f o o t b a l l ","8","v o l l e y ","6","j u d o ","4","b a s k e t b a l l ","10","h a n d b a l l ","8"},
    {"b a s e b a l l ","8","c y c l i s m e ","8","n a t a t i o n ","8","s n o w b o a r d ","9","s k i ","3"},
    {"p a t i n a g e ","8","b i a t h l o n ","8","r o l l e r  ","6","z u m b a ","5","v o i l e ","5"},
    {"y o g a ","4","v t t ","3","p o l o ","4","f u t s a l ","6","t a e k w o n d o ","9"},
    {"b o b s l e i g h ","9","p a r a c h u t i s m e ","12","u l t i m a t e ","8","r a f t i n g ","7","k a y a k ","5"}
  };
  Serial.println("Vous devez trouver un mot de ");
  Serial.print(Sport[niveau][listmot][1]);
  Serial.print(" lettres   !");
  Serial.println("Vous avez le droit de faire 6 fautes pas une de plus !");
  Serial.println(" C'est parti! ");
  nbcaracter = Sport[niveau][listmot][1].length();
  bonmot = Sport[niveau][listmot][0];
}
void setup()
{
  Serial.begin(9600);
  randomSeed(analogRead(0));
}
void loop()
{ 
  using namespace std;
  Serial.println("Bienvenue au jeu du pendu!");
  Serial.println("Selectionner un thème parmis:");
  Serial.println("Voiture");
  Serial.println("Sport");
  Serial.println("Marque");
  int p = 0;
  while(theme != "Sport" && theme!= "Marque" && theme!= "Voiture")
  { 
    if(Serial.available()>0)
    {
      do
      {
        char c = Serial.read();
        if(c != -1)
        {
          theme +=c;
        }
        delay(50);
        p++;
      }while(p<11);
      if(p>10)
      {
        theme += '\0' ;
      }
    }
  }
  Serial.println("Selectionner un niveau :");
  Serial.println("1"); 
  Serial.println("2"); 
  Serial.println("3"); 
  Serial.println("4"); 
  Serial.println("5"); 
  Serial.println();
  int c = 10;
  do
  { 
    if(Serial.available()>0)
    {
      int c = Serial.read();
      if(c != -1)
      {
        delay(50);
        niveau = c ;
        Serial.println(niveau);
      }
    }
  }while((niveau != 49) && (niveau != 50) && (niveau != 51) && (niveau != 52) && (niveau != 53));
  
  Serial.println("Good");
  niveau = niveau-48 ;   
  listmot = random(5);
  if (theme == "Voiture" )
  {
    dvoiture();
  }
  if (theme == "Marque")
  {
    dmarque();
  }
  if (theme == "Sport")
  {
    dsport();
  }
  
  char motencours[nbcaracter];
  for(int w = 0;w<nbcaracter*2;w++)
  {
    if(w & 1)// n est impair
    {
      motencours[w] = ' ';
    }
    else// n est pair
    {
      motencours[w] = '_';
    }
    
  }
  unsigned int nbcaracter1 = nbcaracter*2;
  motencours [nbcaracter1] = '\0' ;
  Serial.print(motencours);
  int faute = 0 ;
  char bonmot1[] = {'a'} ;
  bonmot.toCharArray(bonmot1 , nbcaracter1);
  while( faute < 6  &&  motencours != bonmot1 )
  {
    Serial.println("\nEntrer une lettre!");
    char lettre ;
    do
    {
      int lettre = Serial.read();
    }while(lettre == -1 );
    dfaute = true;
    for (int i = 0;i<nbcaracter*2;i++)
    { 
      if(bonmot[i]==lettre)
      {
        motencours[i] = {lettre};
        dfaute = false;                 
      }
    }
    if(dfaute==true)
    {
      faute++;
    };
    Serial.print(motencours);
  }
  if (faute<6)
  {
    Serial.println("Bravo! Vous avez trouvé le mot ");
    Serial.print(bonmot);
    Serial.print(" en ");
    Serial.print(faute);
    Serial.print(" faute(s)");
  }
  else
  {
    Serial.println("Dommage! Vous avez perdu vous allez être pendu !");
    Serial.println("Le mot était ");
    Serial.print(bonmot);
    Serial.print(".");
  }
}

Bienvenue au jeu du pendu!
Selectionner un thème parmis:
Voiture
Sport
Marque
Selectionner un niveau :
1
2
3
4
5

51„ienvenue au jeu du pendu!
Selectionner un thème parmis:
Voiture
Sport
Marque