union_find_union.c

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   union_find_union.c                                 :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: unite <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/07/21 22:00:39 by unite             #+#    #+#             */
/*   Updated: 2020/09/07 22:44:10 by unite            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "union_find.h"
 
void        union_find_union(t_union_find *uf, size_t p, size_t q)
{
    size_t  root_p;
    size_t  root_q;
 
    if (p >= uf->size || q >= uf->size)
        ds_exit_set(EINVAL);
    root_p = union_find_find(uf, p);
    root_q = union_find_find(uf, q);
    if (root_p == root_q)
        return ;
    if (uf->nchild[root_p] > uf->nchild[root_q])
    {
        uf->parent[root_q] = root_p;
        uf->nchild[root_p] += uf->nchild[q];
    }
    else
    {
        uf->parent[root_p] = root_q;
        uf->nchild[root_q] += uf->nchild[p];
    }
    uf->count--;
    return ;
}