HDU-3172-Virtual Friends

来源：互联网发布：淘宝代金券怎么使用编辑：程序博客网时间：2024/06/04 18:49

ACM模版

描述

题解

带权并查集，这里需要用到字典树来搞一个映射，把名字映射成ID即可。

注意啦，注意啦，这里有一个坑，绝对坑死人，有多组数据，这里说的是T外还要套一层while，真是个暗坑！！！

代码

#include <iostream>#include <string>#include <map>using namespace std;const int MAXN = 2e5 + 10;int pre[MAXN];int sum[MAXN];int total;map<string, int> people; //  用map来处理人名与数字下标之间的对应关系int find(int x){    if (x != pre[x])    {        pre[x] = find(pre[x]);    }    return pre[x];}int join(int x, int y){    int fx = find(x);    int fy = find(y);    if (fx != fy)    {        pre[fx] = fy;        sum[fy] += sum[fx];    }    return sum[fy];}int main(){    int T, n;    string a, b;    while (cin >> T)    {        while (T--)        {            total = 0;            people.clear();            scanf("%d", &n);            while (n--)            {                cin >> a >> b;                if (people.find(a) == people.end())                {                    total++;                    people[a] = total;                    pre[total] = total;                    sum[total] = 1;                }                if (people.find(b) == people.end())                {                    total++;                    people[b] = total;                    pre[total] = total;                    sum[total] = 1;                }                int ans = join(people[a], people[b]);                printf("%d\n", ans);            }        }    }    return 0;}

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