Not sure why the output is printing $ instead of

So I have this program that analyzes a file that has entries of coordinates and then puts them in to an array of structs and then prints out a map of either blank spaces represented by "." or a character if there is a corresponding set of coordinates in the input file. Currently the output is printing $ signs and only a handful of the tiles that it should. I know there is a lot that is probably wrong in my code (this is my first program) but any advice/guidance on what is going wrong would be helpful. Thanks

struct COORD{
    int xV;
    int yV;
    char *floor;
};

This is a function that goes through the array created and retus the character tile:

char* onMap(int x, int y, struct COORD z[]){
    int arraySize = sizeof(z);
    int i;
    char *empty = ".";

    for(i=0; i<arraySize; i++){
        if(z[i].xV == x && z[i].yV == y){
            retu z[i].floor;
        }
    }
    retu empty;
}


int main(){
FILE *input = fopen("C:\Users\John\Desktop\input.txt","r");

int x;
int y;


int count = 0;
char tile[5];
struct COORD coordinates[50];

This parses through the file and creates an array of structs (not sure how to deal with the memory allocation though:

while (fscanf(input, "%i %i %s", &x, &y, tile) != EOF) {                
            coordinates[count].xV = x;
            coordinates[count].yV = y;
            coordinates[count].floor = tile[(strlen(tile)-1)];
            count++;
            while(fgetc(input) != 'n'){};
}


int yCoor =1;
int i;
bool mapping = true;

This has to do with printing out the tiles of the map:

while(mapping){
    for(i = 1; i<31; i++){
        printf("%c", onMap(i, yCoor, coordinates));
        if(i==30 && yCoor<30){
            printf("%i||n", yCoor);
            yCoor++;
            i=0;
        }//increases the x value & resets y
        if(yCoor==30 && i==30){
            mapping = false;
        }
    }

   retu 0;
  }
}

This is the output