Text Justification | Leetcode 68 C++

class Solution {
public:
    vector<string> fullJustify(vector<string>& words, int maxWidth) 
    {
        std::vector<std::string> result;
        int line_index = 0;
        int letter_count = 0;
        int i = 0;
        std::vector<int> dist;
        while(i < words.size())
        {
            letter_count += words[i].length();
            if(i+1 >= words.size())
            {
                dist.push_back(i);
                break;
            }
            else
            {
                if(letter_count ==  maxWidth || letter_count + words[i+1].length() + 1 > maxWidth)
                {
                    line_index++;
                    letter_count = 0;
                    dist.push_back(i);
                    i++;
                    continue;    
                }
                else
                {
                    letter_count++;
                    i++;   
                }
                
            }
            
        }
        
        
        std::string space = " ";
        int start = 0;
        for(int i = 0; i <= line_index; i++)
        {
            std::string l;
            int end = dist[i];    //first line use end+1 words and has end slots
            int len = 0;
            int up, down;
            int slot = end - start ;
            if(slot ==0 ) slot =1;
            
            for(int i = start; i <=end; i++)
            {
                len += words[i].length();
                
            }
            int spaces_left = maxWidth - len;
            
            if(end == start)
            {
              up = spaces_left;
              down = spaces_left;
               
            }
            else
            {
             up = ceil(float(spaces_left) / (end - start));
             down = floor(float(spaces_left) / (end - start));
            }
            
            int x = 0;
            while (spaces_left % slot )
            {
                 x += 1;
                 spaces_left--;
            }
            int up_num = x;
            int down_num = slot-up_num;
            
            if(end != words.size() -1)
            {
                for(int a = start;a < up_num + start; a++)
                {
                    l += words[a];
                    for(int c =0; c < up; c++)
                    {
                        l += space;
                    }
                }
                for(int a = start + up_num; a<end; a++)
                {
                    l += words[a];
                    for(int c =0; c < down;c++)
                    {
                        l += space;
                    }
                }
                l += words[end];
                while(l.length() < maxWidth)
                {
                    l += space;
                }
               
                result.push_back(l);
                
              start = end + 1;  
            }
            else
            {
                if(end == start)
                {
                    l+= words[start];
                    for(int c = 0; c < maxWidth -words[start].length(); c++)
                    {
                        l += space;
                    }
                    result.push_back(l);
                
                }
                
                else
                {
                    
                    while(end >= start)
                    {
                        l += words[start];
                        if(l.length() < maxWidth)
                        
                        {l += space;}
        
                            start++;
                    }
                    while(l.length() <maxWidth)
                    {
                        l += space;
                    }
                    result.push_back(l);
                    
                    
                }
                
            }
                
        }
        return result;
        
            
            
    
        
        
    }
};