Submission #153785

#	Time	Username	Problem	Language	Result	Execution time	Memory
153785		asifthegreat	Arranging Shoes (IOI19_shoes)	C++14	65 / 100	141 ms	12228 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
#include "shoes.h"

const int N = 300000;


long long subtask3(std::vector<int>s){
	set<int>st;
	for(auto i: s)st.insert(i);
	if(st.size() != 2)return 0ll;

	vector<int> v;

	for(int i=0;i<s.size();i++){
		if(s[i]<0)v.push_back(i);
	}
	long long now=0,ans=0;
	for(int i=0;i<s.size();i++){
		if(i%2==0){
			ans+=abs(v[now]-i);
			now++;
		}
	}
	return ans;

	// return ans;
}


long long count_swaps(std::vector<int> s) {
	int n = s.size();
	if(n > 2000){
		int ans_3 = subtask3(s);
		if(ans_3)return ans_3;
	}
	if(true){
		int papa = n/2;
		bool ok = true;
		for(int i = 0; 	i < papa;i++){
			if(s[i] == -s[i+papa] and s[i] < 0)continue;
			ok = false;break;
		}
		if(ok){
			long long nn = (int)s.size()/2ll;
			return nn*(nn-1ll)/2ll;
		}
	}
	int cnt = 0;
	for(int i = 0; i < n;i+=2){
		int k = -69;
		for(int j = i+1; j < n;j++){
			if(s[i] == -s[j]){k = j;break;}
		}
		while(k != i+1){
			swap(s[k],s[k-1]);
			k--;
			cnt++;
		}
		if(s[i] > 0){
			swap(s[i],s[i+1]);cnt++;
		}
	}
	return cnt;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int subtask3(std::vector<int>)':
shoes.cpp:15:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++){
              ~^~~~~~~~~
shoes.cpp:19:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++){
              ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 0 / 15