Graph Theory NO.2 HDU_1272_小希的迷宫_并查集

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;int father[100009];int mark[100009];int Init(){    for(int i=1;i<100009;i++)    {        father[i]=i;    }    return 0;}int Find(int n){    if(father[n]!=n)    {        father[n]= Find(father[n]);    }    return father[n];}int Union(int a,int b){    if(a!=b)    {        father[a]=b;    }    return 0;}int main(){    int i=0;    int flag=0;    int count=0;    int a,b;    Init();    while(1)    {        scanf("%d%d",&a,&b);        if(a==-1&&b==-1)        {            break;        }        if(a&&b)        {            mark[i++]=a;            mark[i++]=b;            if(Find(a)==Find(b))            {                flag=1;            }            Union(Find(a),Find(b));            //printf("%d %d\n",father[a],father[b]);        }        if(a==0&&b==0)        {            if(i==0)            {                printf("Yes\n");                continue;            }            for(int j=0;j<i;j++)            {                if(father[mark[j]]==mark[j])                count++;               // printf("=%d %d\n",mark[j],father[mark[j]]);            }            if(flag==0&&count==1)            {                printf("Yes\n");            }            else            {                printf("No\n");            }            i=0;count=0;flag=0;Init();        }    }    return 0;}/*1 4 1 2 2 12 12 13 12 15 15 11 11 3 3 2 4 5 5 9 5 6 6 7 6 8 9 10 0 01 2 1 3 1 4 2 8 8 9 3 5 5 10 10 12 4 6 6 11 4 70 01 2 3 1 4 1 8 2 8 9 5 3 5 10 10 12 6 4 6 11 4 70 01 4 2 1 2 12 12 13 15 12 15 11 11 3 2 3 4 5 5 9 5 6 6 7 6 8 9 100 06 8  5 3  5 2  6 45 6  0 08 1  7 3  6 2  8 9  7 57 4  7 8  7 6  0 03 8  6 8  6 45 3  5 6  5 2  0 01 2 3 4 0 01 2 0 0nyynyynny*/