1034. Head of a Gang (30)

考察并查集，以及每个集合的信息记录

#include <iostream>#include <vector>#include <map>#include <set>#include <string>#include <algorithm>using namespace std;typedef struct Node{int weight, parent;}Node;typedef struct Call{string a, b;int t;}Call;typedef struct Gang{int head, num, sum, maxw;Gang(){head=-1;num=0;sum=0;maxw=-1;}};vector<Node> p;//disjoint setvector<Call> call;map<string, int> name2id;map<int, string> id2name;set<string> name;int n, k;int realn;//number of distinct nodevoid InitSet(){p.resize(realn);for (int i = 0; i < realn; ++i){p[i].parent = i; p[i].weight = 0;}}void CompressSet(int top, int x){if (top != p[x].parent){CompressSet(top, p[x].parent);p[x].parent = top;}}int FindSet(int x){if (x != p[x].parent){int top = FindSet(p[x].parent);CompressSet(top, x);}return p[x].parent;}void UnionSet(int x, int y){int a = FindSet(x);int b = FindSet(y);p[a].parent = b;}int main(){while(scanf("%d%d",&n,&k)!=EOF){call.resize(n);name.clear();for (int i = 0; i < n; ++i){cin>>call[i].a; cin>>call[i].b; cin>>call[i].t;name.insert(call[i].a); name.insert(call[i].b); }//get the person numberrealn = name.size();name2id.clear();id2name.clear();set<string>::iterator it1;int id = 0;for (it1=name.begin(); it1!=name.end(); it1++,++id)name2id[*it1] = id, id2name[id]=*it1;//build disjoint setInitSet();for (int i = 0; i < call.size(); ++i){int u = name2id[call[i].a]; int v = name2id[call[i].b]; int t = call[i].t;//printf("%d %d %d\n", u, v, t);p[u].weight += t; p[v].weight += t;UnionSet(u, v);}//collect all setmap<int,Gang> allSet;//father and weight of setmap<int,Gang>::iterator it;for (int i = 0; i < realn; ++i){int top = FindSet(i);it = allSet.find(top);if (it != allSet.end()){allSet[top].sum += p[i].weight;allSet[top].num++;if (p[i].weight > allSet[top].maxw){allSet[top].head = i;allSet[top].maxw = p[i].weight;}}else{Gang tmp;tmp.head = i; tmp.maxw = p[i].weight; tmp.num = 1;  tmp.sum = p[i].weight;allSet[top] = tmp;}}//threthold gangstd::vector<Gang> gang;for (it = allSet.begin(); it!=allSet.end(); it++)if (it->second.sum > k*2 && it->second.num > 2) gang.push_back(it->second);//outputvector<pair<string, int>> head;for (int i = 0; i < gang.size(); ++i)head.push_back(make_pair(id2name[gang[i].head],gang[i].num));sort(head.begin(), head.end());printf("%d\n",head.size());for (int i = 0; i < head.size(); ++i)cout<<head[i].first<<" "<<head[i].second<<endl;}return 0;}