1.题目：
输入：map<int,set> mp;
key是集合主键，value是集合元素
mp[1]={1,2,3};
mp[2]={1,3,5};
mp[3]={2,6,7};
mp[4]={1,2,7};
mp[5]={11,12,13};
mp[6]={11,12,13};
mp[7]={21,22,23};
输出:最大连通子图序列
[1,2,3,4],[5,6],[7]
2.解决一：
#include <iostream>
#include<algorithm>
#include <vector>
#include <stack>
#include <set>
#include <map>
using namespace std;
using PIV = pair<int, vector<int>>;
vector<PIV> tree;
int find(int val) {
int root = val;
while (root != tree[root].first) {
root = tree[root].first;
}
while (root != val) {
val = tree[val].first;
tree[val].first = root;
} //路径压缩
return val;
}
void merge(int a, int b) {
int roota = find(a);
int rootb = find(b);
tree[roota].first = rootb;
}
int main() {
tree.resize(23 + 1);
for (int i = 0; i < tree.size(); ++i) {
tree[i] = {
i, {
} };
}
map<int, vector<int>> mp;
mp[1] = {
1,2,3 };
mp[2] = {
1,3,5 };
mp[3] = {
2,6,7 };
mp[4] = {
1,2,7 };
mp[5] = {
11,12,13 };
mp[6] = {
11,12,13 };
mp[7] = {
21,22,23 };
for (auto& kv : mp) {
vector<int>& temp = kv.second;
if (temp.size() == 0) continue;
tree[temp[0]].second.emplace_back(kv.first);
for (int i = 1; i < temp.size(); ++i) {
tree[temp[i]].second.emplace_back(kv.first);
merge(temp[i - 1], temp[i]);
}
}
map<int, set<int>> ans;
for (auto& ele : tree) {
if (ele.second.size())
ans[find(ele.first)].insert(ele.second.begin(), ele.second.end());
}
}
3.解决二：
#include <iostream>
#include<algorithm>
#include <vector>
#include <stack>
#include <set>
#include <map>
using namespace std;
using PIS = pair<int, set<int>>;
unordered_map<int, PIS> tree;
int find(int val) {
if (tree.find(val) == tree.end()) {
//tree[val] = {};
}
else {
int root = val;
while (root != tree[root].first) {
root = tree[root].first;
}
while (root != val) {
val = tree[val].first;
tree[val].first = root;
} //路径压缩
}
return val;
}
void merge(int a, int b) {
int roota = find(a);
int rootb = find(b);
tree[roota].first = rootb;
}
int main() {
map<int, vector<int>> mp;
mp[1] = {
1,2,3 };
mp[2] = {
1,3,5 };
mp[3] = {
2,6,7 };
mp[4] = {
1,2,7 };
mp[5] = {
11,12,13 };
mp[6] = {
11,12,13 };
mp[7] = {
21,22,23 };
for (auto& kv : mp) {
vector<int>& temp = kv.second;
if (temp.size() == 0) continue;
tree[temp[0]].second.insert(kv.first);
if (tree[temp[0]].first == 0)tree[temp[0]].first = temp[0];
for (int i = 1; i < temp.size(); ++i) {
tree[temp[i]].second.insert(kv.first);
if (tree[temp[i]].first == 0)tree[temp[i]].first = temp[i];
merge(temp[i - 1], temp[i]);
}
}
map<int, set<int>> ans;
for (auto& ele : tree) {
//if (ele.second.second.size())
ans[find(ele.second.first)].insert(ele.second.second.begin(), ele.second.second.end());
}
}