C / C ++ | disjoint-set: there on for a check ring of FIG.

 No ring of process analysis:

#include <stdio.h> 
#include <stdlib.h> 
#include <the iostream> 
#define VERTICES. 6 
#define LINE. 5 
the using namespace STD; 
 
/ * 
	parent: set array and solve problems and check 
	VERTICES: setting the number of vertices 
	LINE : set the edge number 
* / 
void initialise (int * parent) 
{ 
	// for initializing the array parent 
	int I; 
	for (I = 0; I <VERTICES; I ++) 
	{ 
		parent [I] = -. 1; 
	 } 
} 
find_root int (int X, parent int []) 
{ 
	// is used to find the root 
	int x_root = X; 
	the while (! parent [x_root] = -1) 
	{ 
		x_root = parent [x_root]; 
	} 
	return x_root; 
 
}
int union_vertices ( int x, int y, int parent [])
{ 
	// for merging two sets. Return 0: merger succeeds, the return 1: merge failed 
	int x_root = find_root (the X-, parent); 
	int y_root = find_root (the y-, parent); 
	printf ( "the X-: The current number is% d, his parent is:% d \ n-", X, x_root); 
	the printf (" Y: is the current number% d, his parent is: D% \ n-", Y, y_root); 
	 
	IF (x_root == y_root) 
	{ 
		return 0; 
	} 
	the else 
	{ 
		parent [x_root] = y_root; // x is connected to the Y 
		return. 1; 
	} 
	 
} 
int main () 
{ 
	int parent [VERTICES] = {0}; 
	initialise (parent); 
	int Edges [the LINE] [2] = { 
			{ } 0,1, {1,2}, {l, 3}, 
	    	{2,4}, {2,5}  
		}; 
	for (int I = 0; I <the LINE; I ++) 
	{
		int Edges X = [I] [0]; 
		int Y = Edges [I] [. 1]; 
		IF (union_vertices (X, Y, parent) == 0) 
		{
			printf ( "ring present"); 
			Exit (0); 
		} 
	} 
	printf ( "No ring"); 
	return 0; 
 }

 

 

Process Analysis presence of a ring:

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
#define VERTICES 6
#define LINE 6 
using namespace std;
 
/*
	parent:数组解决并查集合并问题 
	VERTICES:设定的顶点数
	LINE:设定的边数 
*/
void initialise(int *parent)
{
	//用于parent数组的初始化 
	int i;
	for(i=0;i<VERTICES;i++)
	{
		parent[i]=-1;
	 } 
} 
int find_root(int x,int parent[])
{
	//用来查找根节点 
	int x_root = x;
	while(parent[x_root] != -1)
	{
		x_root = parent[x_root];
	}
	return x_root;

}
int union_vertices(int x,int y,int parent[])
{
	//用于合并两个集合 。返回0：合并成功，返回1：合并失败
	int x_root=find_root(x,parent);
	int y_root=find_root(y,parent);
	printf("x:当前数是%d,他的parent是：%d\n",x,x_root);
	printf("y:当前数是%d,他的parent是：%d\n",y,y_root);
	 
	if(x_root==y_root)
	{
		return 0;
	}
	else
	{
		parent[x_root]=y_root;//将x连到y上 
		return 1;
	}
	 
} 
int main()
{
	int parent[VERTICES]={0};
	initialise(parent);
	int edges[LINE][2] = {
			{0,1},{1,2},{1,3},
	    	{2,4},{2,5},{3,4}
		};
	for(int i=0;i<LINE;++i)
	{
		int x=edges[i][0];
		int y=edges[i][1];
		if(union_vertices(x,y,parent)==0)
		{
			printf("存在环");
			exit(0); 
		}
	}
	printf("没有环");
	return 0;
 } 

 最后一次没有执行“parent[x_root]=y_root;”