Submission #290728

#	Time	Username	Problem	Language	Result	Execution time	Memory
290728		TadijaSebez	Swapping Cities (APIO20_swap)	C++11	100 / 100	449 ms	26604 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back

const int N=100050;
const int inf=1e9+7;
int myc[N],dst[N],tme[N],deg[N];
vector<int> cmp[N],my[N];
void mrg(int u,int v,int w){
	deg[u]++;deg[v]++;
	if(myc[u]==myc[v]){
		int c=myc[u];
		tme[c]=min(tme[c],w);
	}else{
		int c1=myc[u],c2=myc[v];
		if(cmp[c1].size()>cmp[c2].size())swap(c1,c2);
		tme[c2]=min(tme[c2],max(tme[c1],w));
		dst[c1]=w;
		if(deg[u]>2||deg[v]>2)tme[c2]=min(tme[c2],w);
		for(int i:cmp[c1]){
			myc[i]=c2;
			my[i].pb(c2);
			cmp[c2].pb(i);
		}
		cmp[c1].clear();
	}
}

void init(int n,int m,vector<int> u,vector<int> v,vector<int> w){
	vector<int> idx;
	for(int i=0;i<m;i++)idx.pb(i);
	sort(idx.begin(),idx.end(),[&](int i,int j){return w[i]<w[j];});
	for(int i=0;i<n;i++){
		myc[i]=i;
		cmp[i]={i};
		dst[i]=inf;
		tme[i]=inf;
		my[i].pb(i);
	}
	for(int i:idx){
		mrg(u[i],v[i],w[i]);
	}
}

int getMinimumFuelCapacity(int x,int y){
	int i=0,j=0,mn=0;
	while(i<my[x].size()&&j<my[y].size()&&my[x][i]!=my[y][j]){
		if(dst[my[x][i]]<dst[my[y][j]])mn=max(mn,dst[my[x][i]]),i++;
		else mn=max(mn,dst[my[y][j]]),j++;
	}
	if(i==my[x].size()||j==my[y].size())return -1;
	int ans=inf;
	while(i<my[x].size()){
		ans=min(ans,max(tme[my[x][i]],mn));
		mn=dst[my[x][i]];
		assert(j<my[y].size()&&my[x][i]==my[y][j]);
		i++;j++;
	}
	return ans==inf?-1:ans;
}

Compilation message (stderr)

swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:48:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |  while(i<my[x].size()&&j<my[y].size()&&my[x][i]!=my[y][j]){
      |        ~^~~~~~~~~~~~~
swap.cpp:48:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |  while(i<my[x].size()&&j<my[y].size()&&my[x][i]!=my[y][j]){
      |                        ~^~~~~~~~~~~~~
swap.cpp:52:6: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |  if(i==my[x].size()||j==my[y].size())return -1;
      |     ~^~~~~~~~~~~~~~
swap.cpp:52:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |  if(i==my[x].size()||j==my[y].size())return -1;
      |                      ~^~~~~~~~~~~~~~
swap.cpp:54:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |  while(i<my[x].size()){
      |        ~^~~~~~~~~~~~~
In file included from /usr/include/c++/9/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:33,
                 from swap.cpp:2:
swap.cpp:57:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |   assert(j<my[y].size()&&my[x][i]==my[y][j]);
      |          ~^~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 23 / 23
• Subtask 6: 27 / 27