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https://hub.njuu.cf/TheAlgorithms/C-Plus-Plus.git
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93 lines
2.2 KiB
C++
93 lines
2.2 KiB
C++
#include "bits/stdc++.h"
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//#include <boost/multiprecision/cpp_int.hpp>
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//using namespace boost::multiprecision;
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const int mx = 1e6+5;
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const long int inf = 2e9;
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typedef long long ll;
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#define rep(i,n) for(i=0;i<n;i++)
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#define repp(i,a,b) for(i=a;i<=b;i++)
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#define pii pair<int,int>
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#define vpii vector< pii >
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#define vi vector<int>
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#define vll vector<ll>
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#define r(x) scanf("%d",&x)
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#define rs(s) scanf("%s",s)
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#define gc getchar_unlocked
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#define pc putchar_unlocked
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#define mp make_pair
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#define pb push_back
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#define lb lower_bound
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#define ub upper_bound
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#define endl "\n"
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#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
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using namespace std;
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void in(int &x)
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{
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register int c = gc(); x = 0; int neg = 0;
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for(;((c<48 || c>57) && c != '-');c = gc());if(c=='-') {neg=1;c=gc();} for(;c>47 && c<58;c = gc()) {x = (x<<1) + (x<<3) + c - 48;}
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if(neg) x=-x;
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}
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void out (int n) { int N = n, rev, count = 0;rev = N; if (N == 0) { pc('0'); return ;} while ((rev % 10) == 0) { count++; rev /= 10;} rev = 0;while (N != 0) { rev = (rev<<3) + (rev<<1) + N % 10; N /= 10;}while (rev != 0) { pc(rev % 10 + '0'); rev /= 10;}
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while (count--) pc('0');
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}
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ll parent[mx],arr[mx],node,edge;
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vector<pair<ll,pair<ll,ll>>>v;
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void initial()
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{
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int i;
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rep(i,node+edge)
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parent[i] = i;
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}
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int root(int i)
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{
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while(parent[i] != i)
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{
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parent[i] = parent[parent[i]];
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i = parent[i];
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}
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return i;
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}
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void join(int x,int y)
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{
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int root_x = root(x); //Disjoint set union by rank
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int root_y = root(y);
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parent[root_x] = root_y;
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}
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ll kruskal()
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{
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ll mincost=0,i,x,y;
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rep(i,edge)
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{
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x = v[i].second.first;
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y = v[i].second.second;
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if(root(x) != root(y))
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{
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mincost += v[i].first;
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join(x,y);
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}
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}
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return mincost;
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}
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int main(){
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fast;
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while(1)
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{
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int i,j,from,to,cost,totalcost=0;
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cin>>node>>edge; //Enter the nodes and edges
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if(node==0 && edge==0) break; //Enter 0 0 to break out
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initial(); //Initialise the parent array
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rep(i,edge)
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{
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cin>>from>>to>>cost;
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v.pb(mp(cost,mp(from,to)));
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totalcost += cost;
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}
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sort(v.begin(),v.end());
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// rep(i,v.size())
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// cout<<v[i].first<<" ";
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cout<<kruskal()<<endl;
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v.clear();
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}
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return 0;
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}
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