How can I make code for BSQ in C finding biggest square in a map

bsq -- finds and prints the biggest square in a map

must find the largest possible square on a board while avoiding obstacles. The board is represented by a file passed as the program’s argument, respecting those constraints:

• Its first line contains the number of lines on the board (and only that),
• . (representing an empty place) and "o" (representing an obstacle) are the only two allowed characters for the other lines
• All of the lines will be the same length (except the first one)
• There will always be at least one line
• Each line is terminated by \n.

You program must print the board, with some "." replaced by "x" to represent the largest square you found.

5
.....
.o..o
.....
.o...
o...o

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<fcntl.h>

char* take_name(int size, char** array){
    char* name = (char*)malloc(sizeof(char)* 18);
    int y = 1;
    name = array[y];
    return name;
}

char* take_content(char* name){
    char* str = (char*)malloc(sizeof(char)*400), *number = (char*)malloc(sizeof(char)*50);
    int fd = open(name,O_RDONLY), shower, in = 0 ;
    char a;
    while((shower = read(fd, &a, 1)) != 0){
        if(a== 'o' || a == '.' || a == '\n')
        str[in++] = a;
    }
    return str;
}

void remark_condition(char* content){
    
}

void main_procedures(char* content, int size_row_line){
    remark_condition(content);

}

void my_bsq(int size, char** array){
    char*name = take_name(size, array);
    char* content = take_content(name);
    printf("%s\n", content);
    int  sized = 5;
    main_procedures(content, sized);
    
}

int* ar(char** arra){
    int num[20], i = 0, ins = 0;
    for(int y = 0; arra[y]; y++){
        for(int k = 0; arra[y][k]; k++){
            if(arra[y][k] == '.'){
                num[y] = 1;
            }
            else if(arra[y][k] == 'o'){
                num[y] = 0;
            }
        }
    }
    return num;
}

int main(int ac, char** array){
    my_bsq(ac, array);
    return 0;
}